&fml8; error (/usr/local/libexec/fml/error) program corresponds to mead (/usr/local/fml/libexec/mead) of &fml4; Set "$use_error_mail_analyzer_function = yes" to enable error mail analyzer function. By default, $use_error_mail_analyzer_function is "yes". That is, &fml8; error analyzer is enabled by default but &fml4; not. This default behaviour differs from &fml4;. In fact, typical functions of &fml8; are enabled by default. In creating a ML, &fml8; sets up that $ml-admin address (address error messages returned to) calls /usr/local/libexec/fml/error. /usr/local/libexec/fml/error reads a message, analyzes it and creates a chain of Mail::Message objects on memory. Mail::Bounce class analyzes the detail of error based on the objects. Mail::Bounce analylzes which MTA generates the error, which address generates the error, and the error reason. The result is cached at $error_mail_analyzer_cache_dir directory. After some time interval, $error_mail_analyzer_function analyzes the cache data to determine if an address is effective or not. If some address is determined to be removed, &fml8; removes it from member/recipient list. Functions of $error_mail_analyzer_function_select_list are available to determine error or not. Currently "simple_count histgram" and "histgram" algorithm are supported. "histgram" is used by default. Count up the number of error messages from an address and determine whether the address is effective or not. This logic depends on just the total number of errors. If the traffic of ML is high, even a little configuration error of recipients caueses removal of the address soon. This is the main problem of this logic. Count up the number of continuous days that error messages returned. If the number oversomes the threshold, &fml8; removes the corresponding address. The threshold is 14 days by default. That implies continuous errors in 14 days. This logic assumes that the traffic of an ML is at least one message per day. In other words, this logic requires the continuous error. So, little configuration error in the side of recipient has no effect. &fml8; uses this algorithm by default. Caution: If the traffic of the ML is too little under at least one message per day, this algorithm does not work. Error messages data is cached at $error_mail_analyzer_cache_dir directory. IO to cache uses Tie::JournaledDir class via FML::Error::Cache. FML::Error::Cache is a front end (adapter layer) for Tie::JournaledDir class. All IO should be done via methods provided by FML::Error::Cache. You can specify the location the error message is forwarded to as $maintainer_recipient_maps variable. Undefined by default. Error messages are logged at a log file but not forwarded. If enabled, this function forwards the error messages. Just forward it as mime/multipart which contains one messages/rfc822 part. FUTURE PLAN: we forward error messages with the analyzed data. REFERENCE: fml-devel ML 451 around