path: root/cpan/dist/MIME-Lite/README

NAME
    MIME::Lite - low-calorie MIME generator

SYNOPSIS
        use MIME::Lite;
       
    Create a single-part message:

        ### Create a new single-part message, to send a GIF file:
        $msg = MIME::Lite->new(
                     From     =>'me@myhost.com',
                     To       =>'you@yourhost.com',
                     Cc       =>'some@other.com, some@more.com',
                     Subject  =>'Helloooooo, nurse!',
                     Type     =>'image/gif',
                     Encoding =>'base64',
                     Path     =>'hellonurse.gif'
                     );

    Create a multipart message (i.e., one with attachments):

        ### Create a new multipart message:
        $msg = MIME::Lite->new( 
                     From    =>'me@myhost.com',
                     To      =>'you@yourhost.com',
                     Cc      =>'some@other.com, some@more.com',
                     Subject =>'A message with 2 parts...',
                     Type    =>'multipart/mixed'
                     );
        
        ### Add parts (each "attach" has same arguments as "new"):
        $msg->attach(Type     =>'TEXT',   
                     Data     =>"Here's the GIF file you wanted"
                     );  
        $msg->attach(Type     =>'image/gif',
                     Path     =>'aaa000123.gif',
                     Filename =>'logo.gif',
                     Disposition => 'attachment'
                     );

    Output a message:

        ### Format as a string:
        $str = $msg->as_string;
        
        ### Print to a filehandle (say, a "sendmail" stream):
        $msg->print(\*SENDMAIL);

    Send a message:

        ### Send in the "best" way (the default is to use "sendmail"):
        $msg->send;

DESCRIPTION
    In the never-ending quest for great taste with fewer calories, we
    proudly present: *MIME::Lite*.

    MIME::Lite is intended as a simple, standalone module for generating
    (not parsing!) MIME messages... specifically, it allows you to output a
    simple, decent single- or multi-part message with text or binary
    attachments. It does not require that you have the Mail:: or MIME::
    modules installed.

    You can specify each message part as either the literal data itself (in
    a scalar or array), or as a string which can be given to open() to get a
    readable filehandle (e.g., "<filename" or "somecommand|").

    You don't need to worry about encoding your message data: this module
    will do that for you. It handles the 5 standard MIME encodings.

    If you need more sophisticated behavior, please get the MIME-tools
    package instead. I will be more likely to add stuff to that toolkit over
    this one.

MORE EXAMPLES
  Attach a GIF to a text message

    This will create a multipart message exactly as above, but using the
    "attach to singlepart" hack:

        ### Create a new multipart message:
        $msg = MIME::Lite->new(
                     From    =>'me@myhost.com',
                     To      =>'you@yourhost.com',
                     Cc      =>'some@other.com, some@more.com',
                     Subject =>'A message with 2 parts...',
                     Type    =>'TEXT',
                     Data    =>"Here's the GIF file you wanted"
                     );  
        
        ### Attach a part:
        $msg->attach(Type     =>'image/gif',
                     Path     =>'aaa000123.gif',
                     Filename =>'logo.gif'
                     );

  Attach a pre-prepared part (allows fine-tuning):

        $part = MIME::Lite->new(
                     Type     =>'text/html',
                     Data     =>'<H1>Hello</H1>',
                     );
        $part->attr('content-type.charset' => 'UTF8');
        $part->add('X-Comment' => 'A message for you');
        $msg->attach($part);

  Send an HTML document... with images included!

        $msg = MIME::Lite->new(
                     To      =>'you@yourhost.com',
                     Subject =>'HTML with in-line images!',
                     Type    =>'multipart/related'
                     );
        $msg->attach(Type => 'text/html',
                     Data => qq{ <body>
                                 Here's <i>my</i> image: 
                                 <img src="cid:myimage.gif"> 
                                 </body> }
                     );
        $msg->attach(Type => 'image/gif',
                     Id   => 'myimage.gif',
                     Path => '/path/to/somefile.gif',
                     );
        $msg->send();

  Output a message to a filehandle

        ### Write it to a filehandle:
        $msg->print(\*STDOUT); 
         
        ### Write just the header:
        $msg->print_header(\*STDOUT); 
         
        ### Write just the encoded body:
        $msg->print_body(\*STDOUT); 

  Get a message as a string

        ### Get entire message as a string:
        $str = $msg->as_string;
         
        ### Get just the header:
        $str = $msg->header_as_string;
         
        ### Get just the encoded body:
        $str = $msg->body_as_string;

  Change how messages are sent

        ### Do something like this in your 'main':
        if ($I_DONT_HAVE_SENDMAIL) {
           MIME::Lite->send('smtp', "smtp.myisp.net", Timeout=>60);
        }
         
        ### Now this will do the right thing:
        $msg->send;         ### will now use Net::SMTP as shown above

FAQ
  How do I prevent "Content" headers from showing up in my mail reader?

    Apparently, some people are using mail readers which display the MIME
    headers like "Content-disposition", and they want MIME::Lite not to
    generate them "because they look ugly".

    Sigh.

    Y'know, kids, those headers aren't just there for cosmetic purposes.
    They help ensure that the message is *understood* correctly by mail
    readers. But okay, you asked for it, you got it... here's how you can
    suppress the standard MIME headers. Before you send the message, do
    this:

            $msg->scrub;

    You can scrub() any part of a multipart message independently; just be
    aware that it works recursively. Before you scrub, note the rules that I
    follow:

    Content-type
        You can safely scrub the "content-type" attribute if, and only if,
        the part is of type "text/plain" with charset "us-ascii".

    Content-transfer-encoding
        You can safely scrub the "content-transfer-encoding" attribute if,
        and only if, the part uses "7bit", "8bit", or "binary" encoding. You
        are far better off doing this if your lines are under 1000
        characters. Generally, that means you *can* scrub it for plain text,
        and you can *not* scrub this for images, etc.

    Content-disposition
        You can safely scrub the "content-disposition" attribute if you
        trust the mail reader to do the right thing when it decides whether
        to show an attachment inline or as a link. Be aware that scrubbing
        both the content-disposition and the content-type means that there
        is no way to "recommend" a filename for the attachment!

        Note: there are reports of brain-dead MUAs out there that do the
        wrong thing if you *provide* the content-disposition. If your
        attachments keep showing up inline or vice-versa, try scrubbing this
        attribute.

    Content-length
        You can always scrub "content-length" safely.

  How do I give my attachment a [different] recommended filename?

    By using the Filename option (which is different from Path!):

            $msg->attach(Type => "image/gif",
                         Path => "/here/is/the/real/file.GIF",
                         Filename => "logo.gif");

    You should *not* put path information in the Filename.

PUBLIC INTERFACE
  Global configuration

    To alter the way the entire module behaves, you have the following
    methods/options:

    MIME::Lite->header_order()
        When used as a classmethod, this changes the default order in which
        headers are output for *all* messages.

    MIME::Lite->quiet()
        This classmethod can be used to suppress/unsuppress all warnings
        coming from this module.

    MIME::Lite->send()
        When used as a classmethod, this can be used to specify a different
        default mechanism for sending message. The initial default is:

            MIME::Lite->send("sendmail", "/usr/lib/sendmail -t -oi -oem");

        However, you should consider the similar but smarter and taint-safe
        variant:

            MIME::Lite->send("sendmail");

        Or, for non-Unix users:

            MIME::Lite->send("smtp");

    $MIME::Lite::PARANOID
        If true, we won't attempt to use MIME::Base64/MIME::QuotedPrint,
        even if they're available. Default is false.

    $MIME::Lite::AUTO_ENCODE
        If true, automatically choose the encoding from the content type.
        Default is true.

    $MIME::Lite::AUTO_CC
        If true, automatically send to the Cc/Bcc addresses for
        send_by_smtp(). Default is true.

    $MIME::Lite::AUTO_VERIFY
        If true, check paths to attachments right before printing, raising
        an exception if any path is unreadable. Default is true.

  Construction

    new [PARAMHASH]
        *Class method, constructor.* Create a new message object.

        If any arguments are given, they are passed into `build()';
        otherwise, just the empty object is created.

    attach PART
    attach PARAMHASH...
        *Instance method.* Add a new part to this message, and return the
        new part.

        If you supply a single PART argument, it will be regarded as a
        MIME::Lite object to be attached. Otherwise, this method assumes
        that you are giving in the pairs of a PARAMHASH which will be sent
        into `new()' to create the new part.

        One of the possibly-quite-useful hacks thrown into this is the
        "attach-to-singlepart" hack: if you attempt to attach a part (let's
        call it "part 1") to a message that doesn't have a content-type of
        "multipart" or "message", the following happens:

    *       A new part (call it "part 0") is made.

    *       The MIME attributes and data (but *not* the other headers) are cut
            from the "self" message, and pasted into "part 0".

    *       The "self" is turned into a "multipart/mixed" message.

    *       The new "part 0" is added to the "self", and *then* "part 1" is
            added.

        One of the nice side-effects is that you can create a text message
        and then add zero or more attachments to it, much in the same way
        that a user agent like Netscape allows you to do.

    build [PARAMHASH]
        *Class/instance method, initializer.* Create (or initialize) a MIME
        message object. Normally, you'll use the following keys in
        PARAMHASH:

           * Data, FH, or Path      (either one of these, or none if multipart)
           * Type                   (e.g., "image/jpeg")
           * From, To, and Subject  (if this is the "top level" of a message)

        The PARAMHASH can contain the following keys:

    (fieldname)
            Any field you want placed in the message header, taken from the
            standard list of header fields (you don't need to worry about
            case):

                Approved      Encrypted     Received      Sender         
                Bcc           From          References    Subject 
                Cc            Keywords      Reply-To      To 
                Comments      Message-ID    Resent-*      X-*
                Content-*     MIME-Version  Return-Path   
                Date                        Organization

            To give experienced users some veto power, these fields will be
            set *after* the ones I set... so be careful: *don't set any MIME
            fields* (like `Content-type') unless you know what you're doing!

            To specify a fieldname that's *not* in the above list, even one
            that's identical to an option below, just give it with a
            trailing `":"', like `"My-field:"'. When in doubt, that *always*
            signals a mail field (and it sort of looks like one too).

    Data    *Alternative to "Path" or "FH".* The actual message data. This may
            be a scalar or a ref to an array of strings; if the latter, the
            message consists of a simple concatenation of all the strings in
            the array.

    Datestamp
            *Optional.* If given true (or omitted), we force the creation of
            a `Date:' field stamped with the current date/time if this is a
            top-level message. You may want this if using send_by_smtp(). If
            you don't want this to be done, either provide your own Date or
            explicitly set this to false.

    Disposition
            *Optional.* The content disposition, `"inline"' or
            `"attachment"'. The default is `"inline"'.

    Encoding
            *Optional.* The content transfer encoding that should be used to
            encode your data:

               Use encoding:     | If your message contains:
               ------------------------------------------------------------
               7bit              | Only 7-bit text, all lines <1000 characters
               8bit              | 8-bit text, all lines <1000 characters
               quoted-printable  | 8-bit text or long lines (more reliable than "8bit")
               base64            | Largely non-textual data: a GIF, a tar file, etc.

            The default is taken from the Type; generally it is "binary" (no
            encoding) for text/*, message/*, and multipart/*, and "base64"
            for everything else. A value of `"binary"' is generally *not*
            suitable for sending anything but ASCII text files with lines
            under 1000 characters, so consider using one of the other values
            instead.

            In the case of "7bit"/"8bit", long lines are automatically
            chopped to legal length; in the case of "7bit", all 8-bit
            characters are automatically *removed*. This may not be what you
            want, so pick your encoding well! For more info, see the section
            on "A MIME PRIMER".

    FH      *Alternative to "Data" or "Path".* Filehandle containing the data,
            opened for reading. See "ReadNow" also.

    Filename
            *Optional.* The name of the attachment. You can use this to
            supply a recommended filename for the end-user who is saving the
            attachment to disk. You only need this if the filename at the
            end of the "Path" is inadequate, or if you're using "Data"
            instead of "Path". You should *not* put path information in here
            (e.g., no "/" or "\" or ":" characters should be used).

    Id      *Optional.* Same as setting "content-id".

    Length  *Optional.* Set the content length explicitly. Normally, this header
            is automatically computed, but only under certain circumstances
            (see the section on "Limitations").

    Path    *Alternative to "Data" or "FH".* Path to a file containing the
            data... actually, it can be any open()able expression. If it
            looks like a path, the last element will automatically be
            treated as the filename. See "ReadNow" also.

    ReadNow *Optional, for use with "Path".* If true, will open the path and
            slurp the contents into core now. This is useful if the Path
            points to a command and you don't want to run the command over
            and over if outputting the message several times. Fatal
            exception raised if the open fails.

    Top     *Optional.* If defined, indicates whether or not this is a "top-
            level" MIME message. The parts of a multipart message are *not*
            top-level. Default is true.

    Type    *Optional.* The MIME content type, or one of these special values
            (case-sensitive):

                 "TEXT"   means "text/plain"
                 "BINARY" means "application/octet-stream"

            The default is `"TEXT"'.

        A picture being worth 1000 words (which is of course 2000 bytes, so
        it's probably more of an "icon" than a "picture", but I digress...),
        here are some examples:

            $msg = MIME::Lite->build( 
                       From     => 'yelling@inter.com',
                       To       => 'stocking@fish.net',
                       Subject  => "Hi there!",
                       Type     => 'TEXT',
                       Encoding => '7bit',
                       Data     => "Just a quick note to say hi!");
         
            $msg = MIME::Lite->build(
                       From     => 'dorothy@emerald-city.oz',
                       To       => 'gesundheit@edu.edu.edu',
                       Subject  => "A gif for U"
                       Type     => 'image/gif',
                       Path     => "/home/httpd/logo.gif");
         
            $msg = MIME::Lite->build( 
                       From     => 'laughing@all.of.us',
                       To       => 'scarlett@fiddle.dee.de',
                       Subject  => "A gzipp'ed tar file",
                       Type     => 'x-gzip',
                       Path     => "gzip < /usr/inc/somefile.tar |",
                       ReadNow  => 1,
                       Filename => "somefile.tgz");

        To show you what's really going on, that last example could also
        have been written:

            $msg = new MIME::Lite;
            $msg->build(Type     => 'x-gzip',
                        Path     => "gzip < /usr/inc/somefile.tar |",
                        ReadNow  => 1,
                        Filename => "somefile.tgz");    
            $msg->add(From    => "laughing@all.of.us");
            $msg->add(To      => "scarlett@fiddle.dee.de");
            $msg->add(Subject => "A gzipp'ed tar file");  

  Setting/getting headers and attributes

    add TAG,VALUE
        *Instance method.* Add field TAG with the given VALUE to the end of
        the header. The TAG will be converted to all-lowercase, and the
        VALUE will be made "safe" (returns will be given a trailing space).

        Beware: any MIME fields you "add" will override any MIME attributes
        I have when it comes time to output those fields. Normally, you will
        use this method to add *non-MIME* fields:

            $msg->add("Subject" => "Hi there!");

        Giving VALUE as an arrayref will cause all those values to be added.
        This is only useful for special multiple-valued fields like
        "Received":

            $msg->add("Received" => ["here", "there", "everywhere"]

        Giving VALUE as the empty string adds an invisible placeholder to
        the header, which can be used to suppress the output of the
        "Content-*" fields or the special "MIME-Version" field. When
        suppressing fields, you should use replace() instead of add():

            $msg->replace("Content-disposition" => "");

        *Note:* add() is probably going to be more efficient than
        `replace()', so you're better off using it for most applications if
        you are certain that you don't need to delete() the field first.

        *Note:* the name comes from Mail::Header.

    attr ATTR,[VALUE]
        *Instance method.* Set MIME attribute ATTR to the string VALUE. ATTR
        is converted to all-lowercase. This method is normally used to
        set/get MIME attributes:

            $msg->attr("content-type"         => "text/html");
            $msg->attr("content-type.charset" => "US-ASCII");
            $msg->attr("content-type.name"    => "homepage.html");

        This would cause the final output to look something like this:

            Content-type: text/html; charset=US-ASCII; name="homepage.html"

        Note that the special empty sub-field tag indicates the anonymous
        first sub-field.

        Giving VALUE as undefined will cause the contents of the named
        subfield to be deleted.

        Supplying no VALUE argument just returns the attribute's value:

            $type = $msg->attr("content-type");        ### returns "text/html"
            $name = $msg->attr("content-type.name");   ### returns "homepage.html"

    delete TAG
        *Instance method.* Delete field TAG with the given VALUE to the end
        of the header. The TAG will be converted to all-lowercase.

            $msg->delete("Subject");

        *Note:* the name comes from Mail::Header.

    field_order FIELD,...FIELD
        *Class/instance method.* Change the order in which header fields are
        output for this object:

            $msg->field_order('from', 'to', 'content-type', 'subject');

        When used as a class method, changes the default settings for all
        objects:

            MIME::Lite->field_order('from', 'to', 'content-type', 'subject');

        Case does not matter: all field names will be coerced to lowercase.
        In either case, supply the empty array to restore the default
        ordering.

    fields
        *Instance method.* Return the full header for the object, as a ref
        to an array of `[TAG, VALUE]' pairs, where each TAG is all-
        lowercase. Note that any fields the user has explicitly set will
        override the corresponding MIME fields that we would otherwise
        generate. So, don't say...

            $msg->set("Content-type" => "text/html; charset=US-ASCII");

        unless you want the above value to override the "Content-type" MIME
        field that we would normally generate.

        *Note:* I called this "fields" because the header() method of
        Mail::Header returns something different, but similar enough to be
        confusing.

        You can change the order of the fields: see the header_order entry
        elsewhere in this document . You really shouldn't need to do this,
        but some people have to deal with broken mailers.

    filename [FILENAME]
        *Instance method.* Set the filename which this data will be reported
        as. This actually sets both "standard" attributes.

        With no argument, returns the filename as dictated by the content-
        disposition.

    get TAG,[INDEX]
        *Instance method.* Get the contents of field TAG, which might have
        been set with set() or replace(). Returns the text of the field.

            $ml->get('Subject', 0);

        If the optional 0-based INDEX is given, then we return the INDEX'th
        occurence of field TAG. Otherwise, we look at the context: In a
        scalar context, only the first (0th) occurence of the field is
        returned; in an array context, *all* occurences are returned.

        *Warning:* this should only be used with non-MIME fields. Behavior
        with MIME fields is TBD, and will raise an exception for now.

    get_length
        *Instance method.* Recompute the content length for the message *if
        the process is trivial*, setting the "content-length" attribute as a
        side-effect:

            $msg->get_length;

        Returns the length, or undefined if not set.

        *Note:* the content length can be difficult to compute, since it
        involves assembling the entire encoded body and taking the length of
        it (which, in the case of multipart messages, means freezing all the
        sub-parts, etc.).

        This method only sets the content length to a defined value if the
        message is a singlepart with `"binary"' encoding, *and* the body is
        available either in-core or as a simple file. Otherwise, the content
        length is set to the undefined value.

        Since content-length is not a standard MIME field anyway (that's
        right, kids: it's not in the MIME RFCs, it's an HTTP thing), this
        seems pretty fair.

    replace TAG,VALUE
        *Instance method.* Delete all occurences of fields named TAG, and
        add a new field with the given VALUE. TAG is converted to all-
        lowercase.

        Beware the special MIME fields (MIME-version, Content-*): if you
        "replace" a MIME field, the replacement text will override the
        *actual* MIME attributes when it comes time to output that field. So
        normally you use attr() to change MIME fields and add()/replace() to
        change *non-MIME* fields:

            $msg->replace("Subject" => "Hi there!");

        Giving VALUE as the *empty string* will effectively *prevent* that
        field from being output. This is the correct way to suppress the
        special MIME fields:

            $msg->replace("Content-disposition" => "");

        Giving VALUE as *undefined* will just cause all explicit values for
        TAG to be deleted, without having any new values added.

        *Note:* the name of this method comes from Mail::Header.

    scrub
        *Instance method.* This is Alpha code. If you use it, please let me
        know how it goes. Recursively goes through the "parts" tree of this
        message and tries to find MIME attributes that can be removed. With
        an array argument, removes exactly those attributes; e.g.:

            $msg->scrub(['content-disposition', 'content-length']);

        Is the same as recursively doing:

            $msg->replace('Content-disposition' => '');
            $msg->replace('Content-length'      => '');

  Setting/getting message data

    binmode [OVERRIDE]
        *Instance method.* With no argument, returns whether or not it
        thinks that the data (as given by the "Path" argument of `build()')
        should be read using binmode() (for example, when `read_now()' is
        invoked).

        The default behavior is that any content type other than `text/*' or
        `message/*' is binmode'd; this should in general work fine.

        With a defined argument, this method sets an explicit "override"
        value. An undefined argument unsets the override. The new current
        value is returned.

    data [DATA]
        *Instance method.* Get/set the literal DATA of the message. The DATA
        may be either a scalar, or a reference to an array of scalars (which
        will simply be joined).

        *Warning:* setting the data causes the "content-length" attribute to
        be recomputed (possibly to nothing).

    path [PATH]
        Get/set the PATH to the message data.

        *Warning:* setting the path recomputes any existing "content-length"
        field, and re-sets the "filename" (to the last element of the path
        if it looks like a simple path, and to nothing if not).

    fh [FILEHANDLE]
        Get/set the FILEHANDLE which contains the message data.

        Takes a filehandle as an input and stores it in the object. This
        routine is similar to path(); one important difference is that no
        attempt is made to set the content length.

    resetfh [FILEHANDLE]
        Set the current position of the filehandle back to the beginning.
        Only applies if you used "FH" in build() or attach() for this
        message.

        Returns false if unable to reset the filehandle (since not all
        filehandles are seekable).

    read_now
        Forces data from the path/filehandle (as specified by `build()') to
        be read into core immediately, just as though you had given it
        literally with the `Data' keyword.

        Note that the in-core data will always be used if available.

        Be aware that everything is slurped into a giant scalar: you may not
        want to use this if sending tar files! The benefit of *not* reading
        in the data is that very large files can be handled by this module
        if left on disk until the message is output via `print()' or
        `print_body()'.

    sign PARAMHASH
        Sign the message. This forces the message to be read into core,
        after which the signature is appended to it.

    Data    As in `build()': the literal signature data. Can be either a scalar
            or a ref to an array of scalars.

    Path    As in `build()': the path to the file.

        If no arguments are given, the default is:

            Path => "$ENV{HOME}/.signature"

        The content-length is recomputed.

    verify_data
        *Instance method.* Verify that all "paths" to attached data exist,
        recursively. It might be a good idea for you to do this before a
        print(), to prevent accidental partial output if a file might be
        missing. Raises exception if any path is not readable.

  Output

    print [OUTHANDLE]
        *Instance method.* Print the message to the given output handle, or
        to the currently-selected filehandle if none was given.

        All OUTHANDLE has to be is a filehandle (possibly a glob ref), or
        any object that responds to a print() message.

    print_body [OUTHANDLE]
        *Instance method.* Print the body of a message to the given output
        handle, or to the currently-selected filehandle if none was given.

        All OUTHANDLE has to be is a filehandle (possibly a glob ref), or
        any object that responds to a print() message.

        Fatal exception raised if unable to open any of the input files, or
        if a part contains no data, or if an unsupported encoding is
        encountered.

    print_header [OUTHANDLE]
        *Instance method.* Print the header of the message to the given
        output handle, or to the currently-selected filehandle if none was
        given.

        All OUTHANDLE has to be is a filehandle (possibly a glob ref), or
        any object that responds to a print() message.

    as_string
        *Instance method.* Return the entire message as a string, with a
        header and an encoded body.

    body_as_string
        *Instance method.* Return the encoded body as a string. This is the
        portion after the header and the blank line.

        *Note:* actually prepares the body by "printing" to a scalar. Proof
        that you can hand the `print*()' methods any blessed object that
        responds to a `print()' message.

    header_as_string
        *Instance method.* Return the header as a string.

  Sending

    send
    send HOW, HOWARGS...
        *Class/instance method.* This is the principal method for sending
        mail, and for configuring how mail will be sent.

        *As an instance method* (with no arguments), sends the message by
        whatever means has been set up (the default is to use the Unix
        "sendmail" program). Returns whatever the mail-handling routine
        returns: this should be true on success, false/exception on error:

            $msg = MIME::Lite->new(From=>...);
            $msg->send || die "you DON'T have mail!";

        *As a class method* (with a HOW argument and optional HOWARGS), sets
        up how the instance method will work for all objects until further
        notice It treats HOW as a facility name, with optional HOWARGS
        handled by the facility (and returns the previous HOW and HOWARGS as
        an array). There are three facilities:

    "sendmail", ARGS...
            Send a message by piping it into the "sendmail" command. Uses
            the send_by_sendmail() method, giving it the ARGS. This usage
            implements (and deprecates) the `sendmail()' method.

    "smtp", [HOSTNAME]
            Send a message by SMTP, using optional HOSTNAME as SMTP-sending
            host. Uses the send_by_smtp() method.

    "sub", \&SUBREF, ARGS...
            Sends a message MSG by invoking the subroutine SUBREF of your
            choosing, with MSG as the first argument, and ARGS following.

        *For example:* let's say you're on an OS which lacks the usual Unix
        "sendmail" facility, but you've installed something a lot like it,
        and you need to configure your Perl script to use this
        "sendmail.exe" program. Do this following in your script's setup:

            MIME::Lite->send('sendmail', "d:\\programs\\sendmail.exe");

        Then, whenever you need to send a message $msg, just say:

            $msg->send;

        That's it. Now, if you ever move your script to a Unix box, all you
        need to do is change that line in the setup and you're done. All of
        your $msg->send invocations will work as expected.

    send_by_sendmail SENDMAILCMD
    send_by_sendmail PARAM=>VALUE, ...
        *Instance method.* Send message via an external "sendmail" program
        (this will probably only work out-of-the-box on Unix systems).

        Returns true on success, false or exception on error.

        You can specify the program and all its arguments by giving a single
        string, SENDMAILCMD. Nothing fancy is done; the message is simply
        piped in.

        However, if your needs are a little more advanced, you can specify
        zero or more of the following PARAM/VALUE pairs; a Unix-style,
        taint-safe "sendmail" command will be constructed for you:

    Sendmail
            Full path to the program to use. Default is "/usr/lib/sendmail".

    BaseArgs
            Ref to the basic array of arguments we start with. Default is
            `["-t", "-oi", "-oem"]'.

    SetSender
            Unless this is *explicitly* given as false, we attempt to
            automatically set the `-f' argument to the first address that
            can be extracted from the "From:" field of the message (if there
            is one).

            *What is the -f, and why do we use it?* Suppose we did *not* use
            `-f', and you gave an explicit "From:" field in your message: in
            this case, the sendmail "envelope" would indicate the *real*
            user your process was running under, as a way of preventing mail
            forgery. Using the `-f' switch causes the sender to be set in
            the envelope as well.

            *So when would I NOT want to use it?* If sendmail doesn't regard
            you as a "trusted" user, it will permit the `-f' but also add an
            "X-Authentication-Warning" header to the message to indicate a
            forged envelope. To avoid this, you can either (1) have
            SetSender be false, or (2) make yourself a trusted user by
            adding a `T' configuration command to your *sendmail.cf* file
            (e.g.: `Teryq' if the script is running as user "eryq").

    FromSender
            If defined, this is identical to setting SetSender to true,
            except that instead of looking at the "From:" field we use the
            address given by this option. Thus:

                FromSender => 'me@myhost.com'

    send_by_smtp ARGS...
        *Instance method.* Send message via SMTP, using Net::SMTP. The
        optional ARGS are sent into Net::SMTP::new(): usually, these are

            MAILHOST, OPTION=>VALUE, ...

        Note that the list of recipients is taken from the "To", "Cc" and
        "Bcc" fields.

        Returns true on success, false or exception on error.

    sendmail COMMAND...
        *Class method, DEPRECATED.* Declare the sender to be "sendmail", and
        set up the "sendmail" command. *You should use send() instead.*

  Miscellaneous

    quiet ONOFF
        *Class method.* Suppress/unsuppress all warnings coming from this
        module.

            MIME::Lite->quiet(1);       ### I know what I'm doing

        I recommend that you include that comment as well. And while you
        type it, say it out loud: if it doesn't feel right, then maybe you
        should reconsider the whole line. `;-)'

NOTES
  Benign limitations

    This is "lite", after all...

    *   There's no parsing. Get MIME-tools if you need to parse MIME messages.

    *   MIME::Lite messages are currently *not* interchangeable with either
        Mail::Internet or MIME::Entity objects. This is a completely
        separate module.

    *   A content-length field is only inserted if the encoding is binary, the
        message is a singlepart, and all the document data is available at
        `build()' time by virtue of residing in a simple path, or in-core.
        Since content-length is not a standard MIME field anyway (that's
        right, kids: it's not in the MIME RFCs, it's an HTTP thing), this
        seems pretty fair.

    *   MIME::Lite alone cannot help you lose weight. You must supplement your
        use of MIME::Lite with a healthy diet and exercise.

  Cheap and easy mailing

    I thought putting in a default "sendmail" invocation wasn't too bad an
    idea, since a lot of Perlers are on UNIX systems. The out-of-the-box
    configuration is:

         MIME::Lite->send('sendmail', "/usr/lib/sendmail -t -oi -oem");

    By the way, these arguments to sendmail are:

         -t      Scan message for To:, Cc:, Bcc:, etc.
                  
         -oi     Do NOT treat a single "." on a line as a message terminator.
                 As in, "-oi vey, it truncated my message... why?!"
                    
         -oem    On error, mail back the message (I assume to the
                 appropriate address, given in the header).
                 When mail returns, circle is complete.  Jai Guru Deva -oem.

    Note that these are the same arguments you get if you configure to use
    the smarter, taint-safe mailing:

         MIME::Lite->send('sendmail');

    If you get "X-Authentication-Warning" headers from this, you can forgo
    diddling with the envelope by instead specifying:

         MIME::Lite->send('sendmail', SetSender=>0);

    And, if you're not on a Unix system, or if you'd just rather send mail
    some other way, there's always:

         MIME::Lite->send('smtp', "smtp.myisp.net");

    Or you can set up your own subroutine to call. In any case, check out
    the send() method.

WARNINGS
  Good-vs-bad email addresses with send_by_smtp()

    If using send_by_smtp(), be aware that you are forcing MIME::Lite to
    extract email addresses out of a possible list provided in the `To:',
    `Cc:', and `Bcc:' fields. This is tricky stuff, and as such only the
    following sorts of addresses will work reliably:

        username
        full.name@some.host.com
        "Name, Full" <full.name@some.host.com>

    This last form is discouraged because SMTP must be able to get at the
    *name* or *name@domain* portion.

    Disclaimer: MIME::Lite was never intended to be a Mail User Agent, so
    please don't expect a full implementation of RFC-822. Restrict yourself
    to the common forms of Internet addresses described herein, and you
    should be fine. If this is not feasible, then consider using MIME::Lite
    to *prepare* your message only, and using Net::SMTP explicitly to *send*
    your message.

  Formatting of headers delayed until print()

    This class treats a MIME header in the most abstract sense, as being a
    collection of high-level attributes. The actual RFC-822-style header
    fields are not constructed until it's time to actually print the darn
    thing.

  Encoding of data delayed until print()

    When you specify message bodies (in build() or attach()) -- whether by
    FH, Data, or Path -- be warned that we don't attempt to open files, read
    filehandles, or encode the data until print() is invoked.

    In the past, this created some confusion for users of sendmail who gave
    the wrong path to an attachment body, since enough of the print() would
    succeed to get the initial part of the message out. Nowadays,
    $AUTO_VERIFY is used to spot-check the Paths given before the mail
    facility is employed. A whisker slower, but tons safer.

    Note that if you give a message body via FH, and try to print() a
    message twice, the second print() will not do the right thing unless you
    explicitly rewind the filehandle.

    You can get past these difficulties by using the ReadNow option,
    provided that you have enough memory to handle your messages.

  MIME attributes are separate from header fields!

    Important: the MIME attributes are stored and manipulated separately
    from the message header fields; when it comes time to print the header
    out, *any explicitly-given header fields override the ones that would be
    created from the MIME attributes.* That means that this:

        ### DANGER ### DANGER ### DANGER ### DANGER ### DANGER ###
        $msg->add("Content-type", "text/html; charset=US-ASCII");

    will set the exact `"Content-type"' field in the header I write,
    *regardless of what the actual MIME attributes are.*

    *This feature is for experienced users only,* as an escape hatch in case
    the code that normally formats MIME header fields isn't doing what you
    need. And, like any escape hatch, it's got an alarm on it: MIME::Lite
    will warn you if you attempt to `set()' or `replace()' any MIME header
    field. Use `attr()' instead.

  Beware of lines consisting of a single dot

    Julian Haight noted that MIME::Lite allows you to compose messages with
    lines in the body consisting of a single ".". This is true: it should be
    completely harmless so long as "sendmail" is used with the -oi option
    (see the section on "Cheap and easy mailing").

    However, I don't know if using Net::SMTP to transfer such a message is
    equally safe. Feedback is welcomed.

    My perspective: I don't want to magically diddle with a user's message
    unless absolutely positively necessary. Some users may want to send
    files with "." alone on a line; my well-meaning tinkering could
    seriously harm them.

  Infinite loops may mean tainted data!

    Stefan Sautter noticed a bug in 2.106 where a m//gc match was failing
    due to tainted data, leading to an infinite loop inside MIME::Lite.

    I am attempting to correct for this, but be advised that my fix will
    silently untaint the data (given the context in which the problem
    occurs, this should be benign: I've labelled the source code with
    UNTAINT comments for the curious).

    So: don't depend on taint-checking to save you from outputting tainted
    data in a message.

A MIME PRIMER
  Content types

    The "Type" parameter of `build()' is a *content type*. This is the
    actual type of data you are sending. Generally this is a string of the
    form `"majortype/minortype"'.

    Here are the major MIME types. A more-comprehensive listing may be found
    in RFC-2046.

    application
        Data which does not fit in any of the other categories, particularly
        data to be processed by some type of application program.
        `application/octet-stream', `application/gzip',
        `application/postscript'...

    audio
        Audio data. `audio/basic'...

    image
        Graphics data. `image/gif', `image/jpeg'...

    message
        A message, usually another mail or MIME message. `message/rfc822'...

    multipart
        A message containing other messages. `multipart/mixed',
        `multipart/alternative'...

    text
        Textual data, meant for humans to read. `text/plain', `text/html'...

    video
        Video or video+audio data. `video/mpeg'...

  Content transfer encodings

    The "Encoding" parameter of `build()'. This is how the message body is
    packaged up for safe transit.

    Here are the 5 major MIME encodings. A more-comprehensive listing may be
    found in RFC-2045.

    7bit
        Basically, no *real* encoding is done. However, this label
        guarantees that no 8-bit characters are present, and that lines do
        not exceed 1000 characters in length.

    8bit
        Basically, no *real* encoding is done. The message might contain 8-
        bit characters, but this encoding guarantees that lines do not
        exceed 1000 characters in length.

    binary
        No encoding is done at all. Message might contain 8-bit characters,
        and lines might be longer than 1000 characters long.

        The most liberal, and the least likely to get through mail gateways.
        Use sparingly, or (better yet) not at all.

    base64
        Like "uuencode", but very well-defined. This is how you should send
        essentially binary information (tar files, GIFs, JPEGs, etc.).

    quoted-printable
        Useful for encoding messages which are textual in nature, yet which
        contain non-ASCII characters (e.g., Latin-1, Latin-2, or any other
        8-bit alphabet).

VERSION
    $Id: Lite.pm,v 2.108 2001/03/30 06:16:54 eryq Exp $

CHANGE LOG
    Version 2.108
        New `field_order()' allows you to set the header order, both on a
        per-message basis, and package-wide. *Thanks to Thomas Stromberg for
        suggesting this.*

        Added code to try and divine "sendmail" path more intelligently.
        *Thanks to Slaven Rezic for the suggestion.*

    Version 2.107   (2001/03/27)
        Fixed serious bug where tainted data with quoted-printable encoding
        was causing infinite loops. The "fix" untaints the data in question,
        which is not optimal, but it's probably benign in this case. *Thanks
        to Stefan Sautter for tracking this nasty little beast down.*
        *Thanks to Larry Geralds for a related patch.*

            "Doctor, O doctor:
               it's painful when I do *this* --" 
            "Simple: don't *do* that." 

        Fixed bugs where a non-local `$_' was being modified... again! Will
        I never learn? *Thanks to Maarten Koskamp for reporting this.*

            Dollar-underscore
               can poison distant waters;
           'local' must it be.

        Fixed buglet in `add()' where all value references were being
        treated as arrayrefs, instead of as possibly-self-stringifying
        object refs. Now you can send in an object ref as the 2nd argument.
        *Thanks to dLux for the bug report.*

            That ref is a string?
               Operator overload
            has ruined my day.

        Added "Approved" as an acceptable header field for `new()', as per
        RFC1036. *Thanks to Thomax for the suggestion regarding MIME-tools.*

        Small improvements to docs to make different uses of attach() and
        various arguments clearer. *Thanks to Sven Rassman and Roland Walter
        for the suggestions.*

    Version 2.106   (2000/11/21)
        Added Alpha version of scrub() to make it easy for people to
        suppress the printing of unwanted MIME attributes (like Content-
        length). *Thanks to the many people who asked for this.*

        Headers with empty-strings for their values are no longer printed.
        This seems sensible, and helps us implement scrub().

    Version 2.105   (2000/10/14)
        The regression-test failure was identified, and it was my fault.
        Apparently some of the \-quoting in my "autoloaded" code was making
        Perl 5.6 unhappy. For this nesting-related idiocy, a nesting kaiku.
        *Thanks to Scott Schwartz for identifying the problem.*

            In a pattern, my
               backslash-s dwells peacefully,
            unambiguous --
             
               but I embed it
                  in a double-quoted string    
               doubling the backslash --
             
                  interpolating
                     that same double-quoted string 
                  in other patterns --
                   
                     and, worlds within worlds,
                        I single-quote the function
                     to autoload it -- 
            
                  changing the meaning
               of the backslash and the 's';
            and Five-Point-Six growls.

    Version 2.104   (2000/09/28)
        Now attempts to load and use Mail::Address for parsing email
        addresses *before* falling back to our own method. *Thanks to
        numerous people for suggesting this.*

            Parsing addresses
               is too damn hard. One last hope:
            Let Graham Barr do it!

        For the curious, the version of Mail::Address appears as the "A"
        number in the X-Mailer:

            X-Mailer: MIME::Lite 2.104  (A1.15; B2.09; Q2.03)

        Added FromSender option to send_by_sendmail(). *Thanks to Bill
        Moseley for suggesting this feature.*

    Version 2.101   (2000/06/06)
        Major revision to print_body() and body_as_string() so that "body"
        really means "the part after the header", which is what most people
        would want in this context. This is not how it was used 1.x, where
        "body" only meant "the body of a simple singlepart". Hopefully, this
        change will solve many problems and create very few ones.

        Added support for attaching a part to a "message/rfc822", treating
        the "message" type as a multipart-like container.

        Now takes care not to include "Bcc:" in header when using
        send_by_smtp, as a safety precaution against qmail's behavior.
        *Thanks to Tatsuhiko Miyagawa for identifying this problem.*

        Improved efficiency of many stringifying operations by using string-
        arrays which are joined, instead of doing multiple appends to a
        scalar.

        Cleaned up the "examples" directory.

    Version 1.147   (2000/06/02)
        Fixed buglet where lack of Cc:/Bcc: was causing extract_addrs to
        emit "undefined variable" warnings. Also, lack of a "To:" field now
        causes a croak. *Thanks to David Mitchell for the bug report and
        suggested patch.*

    Version 1.146   (2000/05/18)
        Fixed bug in parsing of addresses; please read the WARNINGS section
        which describes recommended address formats for "To:", "Cc:", etc.
        Also added automatic inclusion of a UT "Date:" at top level unless
        explicitly told not to. *Thanks to Andy Jacobs for the bug report
        and the suggestion.*

    Version 1.145   (2000/05/06)
        Fixed bug in encode_7bit(): a lingering `/e' modifier was removed.
        *Thanks to Michael A. Chase for the patch.*

    Version 1.142   (2000/05/02)
        Added new, taint-safe invocation of "sendmail", one which also sets
        up the `-f' option. Unfortunately, I couldn't make this automatic:
        the change could have broken a lot of code out there which used
        send_by_sendmail() with unusual "sendmail" variants. So you'll have
        to configure "send" to use the new mechanism:

            MIME::Lite->send('sendmail');       ### no args!

        *Thanks to Jeremy Howard for suggesting these features.*

    Version 1.140   (2000/04/27)
        Fixed bug in support for "To", "Cc", and "Bcc" in send_by_smtp():
        multiple (comma-separated) addresses should now work fine. We try
        real hard to extract addresses from the flat text strings. *Thanks
        to John Mason for motivating this change.*

        Added automatic verification that attached data files exist, done
        immediately before the "send" action is invoked. To turn this off,
        set $MIME::Lite::AUTO_VERIFY to false.

    Version 1.137   (2000/03/22)
        Added support for "Cc" and "Bcc" in send_by_smtp(). To turn this
        off, set $MIME::Lite::AUTO_CC to false. *Thanks to Lucas Maneos for
        the patch, and tons of others for the suggestion.*

        Chooses a better default content-transfer-encoding if the content-
        type is "image/*", "audio/*", etc. To turn this off, set
        $MIME::Lite::AUTO_ENCODE to false. *Thanks to many folks for the
        suggestion.*

        Fixed bug in QP-encoding where a non-local `$_' was being modified.
        *Thanks to Jochen Stenzel for finding this very obscure bug!*

        Removed references to `$`', `$'', and `$&' (bad variables which slow
        things down).

        Added an example of how to send HTML files with enclosed in-line
        images, per popular demand.

    Version 1.133   (1999/04/17)
        Fixed bug in "Data" handling: arrayrefs were not being handled
        properly.

    Version 1.130   (1998/12/14)
        Added much larger and more-flexible send() facility. *Thanks to
        Andrew McRae (and Optimation New Zealand Ltd) for the Net::SMTP
        interface. Additional thanks to the many folks who requested this
        feature.*

        Added get() method for extracting basic attributes.

        New... "t" tests!

    Version 1.124   (1998/11/13)
        Folded in filehandle (FH) support in build/attach. *Thanks to Miko
        O'Sullivan for the code.*

    Version 1.122   (1998/01/19)
        MIME::Base64 and MIME::QuotedPrint are used if available.

        The 7bit encoding no longer does "escapes"; it merely strips 8-bit
        characters.

    Version 1.121   (1997/04/08)
        Filename attribute is now no longer ignored by build(). *Thanks to
        Ian Smith for finding and patching this bug.*

    Version 1.120   (1997/03/29)
        Efficiency hack to speed up MIME::Lite::IO_Scalar. *Thanks to David
        Aspinwall for the patch.*

    Version 1.116   (1997/03/19)
        Small bug in our private copy of encode_base64() was patched.
        *Thanks to Andreas Koenig for pointing this out.*

        New, prettier way of specifying mail message headers in `build()'.

        New quiet method to turn off warnings.

        Changed "stringify" methods to more-standard "as_string" methods.

    Version 1.112   (1997/03/06)
        Added `read_now()', and `binmode()' method for our non-Unix-using
        brethren: file data is now read using binmode() if appropriate.
        *Thanks to Xiangzhou Wang for pointing out this bug.*

    Version 1.110   (1997/03/06)
        Fixed bug in opening the data filehandle.

    Version 1.102   (1997/03/01)
        Initial release.

    Version 1.101   (1997/03/01)
        Baseline code.

TERMS AND CONDITIONS
    Copyright (c) 1997 by Eryq. Copyright (c) 1998 by ZeeGee Software Inc.
    All rights reserved. This program is free software; you can redistribute
    it and/or modify it under the same terms as Perl itself.

    This software comes with NO WARRANTY of any kind. See the COPYING file
    in the distribution for details.

NUTRITIONAL INFORMATION
    For some reason, the US FDA says that this is now required by law on any
    products that bear the name "Lite"...

        MIME::Lite                | 
        ------------------------------------------------------------
        Serving size:             | 1 module
        Servings per container:   | 1
        Calories:                 | 0
        Fat:                      | 0g
          Saturated Fat:          | 0g

    Warning: for consumption by hardware only! May produce indigestion in
    humans if taken internally.

AUTHOR
    Eryq (eryq@zeegee.com). President, ZeeGee Software Inc.
    (http://www.zeegee.com).

    Created: 11 December 1996. Ho ho ho.