Running amavisd-new on MX hosts?

[Rich Wales]

> If the plan was to run a content filter in a post-queue setup,
> there is no advantage in running it on a MX, as the option of
> rejecting a message is already lost.

Except, perhaps, if you want to reduce the amount of traffic to the mail
server caused by spam, by quarantining spam on the MX server(s).
Depending on the amount of mail involved, the mail server's network
bandwidth, ISP traffic limits, etc., this might or might not be worthwhile.

> Even if amavisd is invoked by a MX, it need not run on the
> same host as a mailer. Two MX hosts may share a single amavisd
> service, as they all communicate through a standard SMTP / TCP
> network protocol.

Of course, you'd need to be prepared to handle the situation where an
incoming message arrives when the MX host is up but the host running the
amavisd service is down.

Rich Wales
richw at richw.org