The exim project website has some good examples http://www.exim.org/exim-html-current/doc/html/spec_html/filter_ch-exim_filter_files.html.
We also have example .public.forward files in the following section.
NathanKennedy
It is possible to set up custom filters to do fancy things based on the X-Spam-Level: header. Here is NathanKennedy's ~/.public/.forward file. He finds that the default setting of 5.0 is too wimpy, and lets too much spam into his inbox. Virtually no ham that he gets scores less than 3.0, whereas a lot of spam scores less than 5.0, so he'd rather have anything over 3.0 go to his Junk folder. At the same time, he doesn't want to waste time, cycles, disk space or bandwidth with spam over 9.0. Most of his spam does score 9.0, and this goes straight to /dev/null (immediately disposed of) with this filter.
Finally, he has all HCoop list email go into a special HCoop folder.
Without further ado:
# Exim filter logfile $home/.logs/mail/spamlog if $header_subject contains "[HCoop" then save $home/Maildir/.HCoop/ finish endif if "${if def:h_X-Spam-Level {def}{undef}}" is "def" then if $h_X-Spam-Level: begins "\*\*\*\*\*\*\*\*\*" then save "/dev/null" 660 else if $h_X-Spam-Level: begins "\*\*\*" then save $home/Maildir/.Junk/ endif endif finish endif if "${if def:h_X-Spam-Flag {def}{undef}}" is "def" then save $home/Maildir/.Junk/ finish endif
FrankBynum
# Exim filter # Lists if $h_to: contains "lists.hcoop.net" then save $home/Maildir/.Causes.Hcoop/ elif $h_to: contains "groups.barackobama.com" then save $home/Maildir/.Causes.Obama/ elif $h_X-Generated-By: CONTAINS "Launchpad" then save $home/Maildir/.Causes.Floss/ # Junk elif $h_X-Spam-Level: begins "\*\*\*\*\*\*\*\*\*" then save "/dev/null" 660 elif $h_X-Spam-Level: begins "\*\*\*\*" then save $home/Maildir/.Junk.Spam/ elif $h_X-Spam-Status: contains "BAYES_99" then save $home/Maildir/.Junk.Bayes_99/ endif
StephenMichel
This template filters anything sent to me@example.com or to me+$anything@example.com into the sub-folder me. This is useful if you have one or more aliases set up, to filter mail for each alias into its own subfolder.
if "$h_to:, $h_cc:, $h_bcc:" matches "me(\\\\+[\\^@]\\*)\\?@example\\\\.com" then save $home/Maildir/.me/ endif
Björn Lindström
Some rules using matches which allows PCRE style regular expressions.
# Exim filter # Log logfile $home/.logs/mail/exim.log # Don't do any filtering on delivery failure messages from Exim. if error_message then finish endif # Spam if "${if def:h_X-Spam-Level {def}{undef}}" is "def" then # Drops mail with a spam level above 9 if $h_X-Spam-Level: matches "^\\\\*{9}" then seen finish # Puts other mail with a spam level above 3 into "Spam" elif $h_X-Spam-Level: matches "^\\\\*{3}" then save $home/Maildir/.Spam/ finish endif elif "${if def:h_X-Spam-Flag {def}{undef}}" is "def" then # Puts other mail with spam flag set into "Spam" also. save $home/Maildir/.Spam/ finish endif # Filter into folders if "$h_to:, $h_cc:, $h_bcc:" matches "\\\\b((bkhl|upp?sala|relax)@fandom\\\\.se|upp?salafandom@dang\\\\.se|fanac@lists\\\\.lysator\\\\.liu\\\\.se)\\\\b" then save $home/Maildir/.Fandom/ elif "$h_to:, $h_cc:, $h_bcc:" matches "@(\\.*\\\\.)?hcoop\\\\.net\\\\b" then save $home/Maildir/.HCoop/ endif
Filtering out bogus bounce messages
AdamChlipala found a trick a while back that allows you to filter out bogus bounce messages. https://lists.hcoop.net/pipermail/hcoop-discuss/2007-January/000745.html