Open Source OpenBSD Email Spam Filter Software

qSheff is a wrapper for the qmail queue that scans email for viruses and spam. It is simple and powerful. It features the ability to quarantine, nice logging, subject filtering, body filtering, attachment blocking, a blackhole and white/black lists.

This is a milter which scans emails with CRM114

ClamCour is a Courier-MTA multithread filter that allows Courier to scan mail for viruses using Clam Antivirus package. Attachments can be "quarantinated" and custom domain-based email reports can be sent.

Protect your company's email and browsing with your GoodCrypto private server. * Protects email metadata and resists traffic analysis * Automatic encryption, decryption, and key management * All private keys stay on *your* server * Users don't change their email or browser software * Blocks web malware * Runs on your private server * Completely decentralized

This is a milter which scans emails with qsf (Quick Spam Filter)

TLim (Transaction Limiter) TLim is a patch that spam-hardens sendmail against both inbound and outbound abuse. TLim counts the number of transactions an IP performs. Should the IP violate admin-defined limits, it is sanctioned via a null route.

dspam-filter is a filter to invoke the anti-spam tool DSPAM directly from the embedded maildrop in vpopmail via dot-qmail forwarding. DSPAM masquerades as the email server's LDA. However most users of Qmail prefer to leave the qmail-queue intact.

a fast email client for console that support pop3 and smtp protocols also with ssl connections and more paranoic futures...

This is a very simple and radical spam filter, combining dns-validation with the challenge/respond approach.