Messaging Platform based on indimail-mta, Courier-IMAP for IMAP/POP3, fetchmail for mail retreival

mail filter to replace MS Word/HTML attachments with plain text

Evolution filters to scan mail for viruses with ClamAV.

Tame your inbox with these Gmail mail filters for Google My Business

Roundcube plugin to retroactively apply Sieve filter rules to existing messages. Companion to managesieve.