Content Filter

Content Filter

The Amavid content filter is a high-performance interface between Postfix, SpamAssassin, and ClamAV. Amavis has been the gold standard used by large email providers for over a decade. More information about Amavis can be found here: https://www.amavis.org/

Features

  • Block spam, viruses, banned attachments, and even messages with non-compliant email headers.
  • Supports move, quarantine, block, or tag subject spam actions.
  • Supports setting server, domain, and mailbox level anti-spam and anti-virus policies.
  • Supports blacklisting and whitelisting at the server, domain, or mailbox levels.
  • Does not let mail pass unchecked when unpredictable things happen or when mail is too big. Mail stays in the Postfix queue.
  • Optionally call one or more anti-virus scanners - the current list includes more than 40 AV scanners and is easily extended.
  • Optionally check MIME types, file names and content types of decoded mail parts against a list of banned names and content types.
  • Optionally check the mail header for invalid characters and some other common violations of rfc2822.
  • Optionally decompresses multiple formats: MIME, uuencode, xxencode, BinHex, compress, gzip, bzip, bzip2, zip, 7-zip, freeze, lzop, tar, cpio, rpm, deb, rar, arc, arj, zoo, lha(lzh), tnef, ole, cab.
  • SpamAssassin check is called only once per message regardless of the number of recipients.
  • Provides a SQL log of all processed email in the Warden database.
  • Standards compliant and adheres tightly to multiple RFC specifications.

Restarting Amavis

Centos / RHEL / CloudLinux

// restart amavis
systemctl restart amavisd.service

// amavis log file
tail -f /var/log/maillog  

Debian / Ubuntu

// restart amavis
/etc/init.d/amavis restart

// amavis log file
tail -f /var/log/maillog 

Related Files

File Description
/etc/amavisd/amavisd.conf Main configuration file for Amavis on Centos / RHEL
/etc/amavisd/warden.conf Warden configuration file for Amavis on Centos / RHEL
/etc/amavis/conf.d/99-warden.conf Warden configuration file for Amavis on Debian / Ubuntu