From iRedMail

In iRedMail, Amavisd provides below features:

• content-based spam scanning (invoke SpamAssassin)
• Virus scanning (invoke ClamAV)
• DKIM singing
• DKIM verification (through SpamAssassin + Perl module)
• SPF verification (through SpamAssassin + Perl module)
• Disclaimer (throught AlterMIME)

Stop virus/spam scanning, keep DKIM signing/verification and Disclaimer

If you want to disable virus and spam scanning, but keep DKIM signing and disclaimer, please try this:

• Keep "content_filter =" setting in Postfix main.cf.

content_filter = smtp-amavis:[127.0.0.1]:10024

• Find below lines in /etc/amavisd/amavisd.conf:

# @bypass_virus_checks_maps = (1);  # controls running of anti-virus code
# @bypass_spam_checks_maps  = (1);  # controls running of anti-spam code

Uncomment above lines (removing "# " at the beginning of each line), and restart Amavisd service.

Completely disable all features

If you want to completely disable spam and virus scanning services, steps:

1. Comment out 'content_filter = smtp-amavis:[127.0.0.1]:10024' in Postfix config file main.cf, and restart Postfix service.
2. Disable network services: Amavisd, ClamAV.

Notes:

• ClamAV and SpamAssassin will be invoked by Amavisd, so if you disable Amavisd, those two are disabled too.
• SpamAssassin doesn't have daemon service running in iRedMail solution, so there's no need to stop SpamAssassin service.