Mail filter
A mail filter , or Milter for short , is a computer program or module of a program that automatically processes incoming e-mails according to certain criteria.
A classic area of application is sorting electronic mail into various mailboxes. This can e.g. B. using keywords in the subject or content of the mail, based on the size, the sender or other criteria and thus allows, for example, to separate private mails from the contributions of mailing lists .
Further options for mail filters are the automatic answering of mails (see also autoreply ), the removal or conversion of file attachments , virus scanners for malware , spam filters for unwanted messages, content filters for unwanted content, or the operation of simple mailing lists .
Mail filters can be located on a mail server (MTA or MRA) or in the e-mail program (MUA) . The filter functions built into e-mail programs are usually not as flexible as the special independent mail filter programs.