- ClamAnti Virus scanner is open source and works great with qmail.
- simscan Works with the QMAILQUEUE patch to scan incoming mail during the SMTP conversation to reject viruses before they are accepted by qmail.
- Jason Haar wrote Qmail-Scanner (also known as scan4virus), which scans all gatewayed Email for certain characteristics. It is typically used for its anti-virus protection functions, in which case it is used in conjunction with commercial virus scanners. but also enables a site to react to Email (at a server/site level) that contains specific strings in particular headers, or particular attachment filenames or types e.g. *.VBS attachments).
- There are also patched version of Qmail-scanner at qmail-scanner-st that enhances spam-handling (for example: can delete spam)
- AMaViS is A Mail Virus Scanner.
- OdeiaVir integrates virus scanning into qmail.
- Len Budney has qscanq. Qscanq provides a virus-scanning wrapper for qmail. Qscanq scans every email message submitted to qmail before allowing it to be added to qmail's mail queue. Infected emails are rejected, not bounced, so you won't have to deal with double-bounces during virus outbreaks.
- Baris Simsek wrote qSheff, a qmail-queue replacement for content filtering and virus scanning.
- F-Prot Antivirus for UNIX Mail Servers supports in-transit scanning directly by using a qmail-queue replacement. F-Prot Antivirus runs as Daemon Scanner.
- Kaspersky Lab includes qmail support for their AVP anti-virus program.
- Central Command's Vexira MailArmor has qmail support.
- F-Prot supports use of the Anomy sanitizer with qmail.
- Adam Aube's block_file.pl rejects messages using file name and/or MIME type patterns.
- Jozef Hitzinger wrote How to filter ms e-mail worms.
- The qmail all in one patch supports a very fast SMTP DATA stream scanning with clamd. It rejects viruses immediately at SMTP level.
- Russell Nelson has an antivirus patch for qmail-smtpd, with some contributions from Charles Cazabon.
- Paul Gregg HELO FQDN patch rejects HELO commands whose parameter has no dot.