Edit /usr/local/etc/fml/site_default_config.cf to apply the effect to all ML's. No tag of subject. This is default in &fml8; (default site_default_config.cf includes this configuration). article_header_rewrite_rules -= rewrite_article_subject_tag This means header rewrite rules minus "adding subject tag" operation. Prepend office# at X-ML-Name:. That is, mlname is changed to office#mlname. # office#$mlname outgoing_mail_header_x_ml_name = office#$ml_name Anybody can post to this ML since customers send mails to this address. article_post_restrictions = permit_anyone In this case, anybody including system special accounts e.g. root, postmaster can post. Disable almost all filters since a lot of customer messages looks something wrong. use_article_filter = no Change spool type as subdir since the number of articles may become over million. spool_type = subdir Disable command mail. use_command_mail_function = no If someboby want to use command mail (e.g. by CGI), we use this variable. It is recommended to remove proper alias entries if could to ensure the command mail is prohibited. Edit /usr/local/etc/fml/site_default_config.cf to apply the effect to all ML's. Add uppercase-ed ML name to the article subject tag. article_subject_tag = (\U$ml_name\E %05d) For example, an article of support@example.co.jp has the tag Subject: (SUPPORT 10000) . Allow the use of command mail, which comes only from the specific domain (my domain e.g. example.co.jp). This hook enables it. $command_verify_request_end_hook = q{ my $cred = $curproc->credential(); my $from = $cred->sender(); unless ($from =~ /\@example\.co\.jp/i) { $curproc->stop_this_process(); $curproc->logerror("deny command request from $from"); } };