Max. message size (attachment size)

Open data/conf/postfix/extra.cf and set the message_size_limit accordingly in bytes. See main.cf for the default value.

You will also need to adjust message size in Rspamd and Clamav configurations:

  • in data/conf/rspamd/local.d/options.inc add max_message parameter, check Rspamd Docs for defaults
  • in data/conf/rspamd/local.d/external_services.conf adjust max_size parameter for oletools
  • in data/conf/rspamd/local.d/antivirus.conf adjust max_size parameter for clamav
  • in data/conf/clamav/clamd.conf adjust MaxScanSize and MaxFileSize

Restart Postfix, Rspamd and Clamav:

docker compose restart postfix-mailcow rspamd-mailcow clamd-mailcow

docker-compose restart postfix-mailcow rspamd-mailcow clamd-mailcow