Author: David Woodhouse Date: To: Johann Spies CC: exim-users Subject: Re: [Exim] exim4-exiscan-spamassassin
On Fri, 2004-01-30 at 17:24 +0200, Johann Spies wrote: > Yes, I have heard that spammers do that. On mail1 and mail2 I will
> also run spamassassin which will then not scan the mail coming from
> spamscanner because of the header added by the latter.
>
> At the moment spamassassin is killing mail1 and mail2 when we try and
> do scan all the mail. This is an effort to reduce the load on the two
> mail servers. Spamscanner will be a much more powerful machine than
> the two mailservers.
My solution for this was to make the 'primary' but CPU-challenged mail
host IPv6-only, and hence to offload the majority of the spamassassin
load onto the IPv4-capable MX backup. Only a trickle of mail comes in
directly to the IPv6-only box.
Then I didn't have to play with special routing, I just let it act as a
normal MX backup.
Whatever approach you take, I'd recommend you do recipient verification
callouts on the spam-scanner box for the domains you're relaying for.
But do remember to use defer_ok if you want your spam-scanner to
continue to accept mail while the primary boxen are down, and hence act
as a real MX backup.