How does postfix call spamd and clamd?

I have been digging through postfix’s configuration files and cannot seem to figure out how postfix calls spamd and clamd to do what they do.

For example, in exim you would add av_scanner : /path/to/clamd. I see no such thing in Postfix. Google isn’t really helping with this.

Thanks for your help


That’s all setup behind the scenes by Virtualmin. What’s happening is that procmail is calling both ClamAV and SpamAssassin prior to delivery.

So long as procmail is being used as the delivery agent, both ClamAV and SpamAssassin should be “in the loop” so to speak (well, assuming the anti-virus and anti-spam features are checked in the Virtual Server settings).


Thanks for the help! Given that virtualmin supports postfix much better than exim, I am open to learning how postfix does its thing.

Since Procmail is taking over talking to clamd, how do I go about adding the tag line “Message checked for malware being being delivered” in the headers? Exim had a setting for adding that as well directly in the config.