home *** CD-ROM | disk | FTP | other *** search
- ###########################################################################
- # [Reject empty MAIL FROM with multiple recipients]
- #
- # Description: "When the MAIL FROM of a message is blank, reject messages with multiple recipients"
- # Keywords: "MAIL FROM, RCPT TO, error mail, rejection methods, limits, recipients, number"
- # Category: "Junk mail detection"
- # Format: "{TRUE OR FALSE}"
- #
- # Message with a blank MAIL FROM value are allowed on the Internet, because
- # they are used by mail programs to report errors, and the blank MAIL FROM is
- # used to prevent mail loops (automated programs can't endlessly send automated
- # messages to each other with a blank MAIL FROM, since this return address
- # is not included).
- #
- # However, the only usual legitimate use of a blank MAIL FROM is for these
- # mail systems to exchange bounce information (such as "message undeliverable
- # messages). Human beings should not be sending messages with a blank
- # MAIL FROM to each other, and it certainly should not be the case that a
- # message with a blank MAIL FROM is being delivered to multiple people.
- # People who send junk mail sometimes exploit this blank MAIL FROM capability
- # to hide who they are, to further evade identification.
- #
- # Since system messages are almost always only To: one account, and not to
- # several, it is legitimate to reject messages that have a blank MAIL FROM
- # but which attempt to send to multiple recipients. This filter will reject
- # a message that has a blank MAIL FROM, if more than one recipient is
- # specified with the RCPT TO command.
- #
- # This filter has a very low false positive rate, and can be useful for
- # blocking certain kinds of junk mail.
- #
- # By default, this setting is disabled.
- #
- # Instructions: "Please enter the word TRUE or the word FALSE below."
- FALSE
-