MailScanner load

Scott Silva ssilva at
Wed Aug 16 22:01:28 IST 2006

Steve Campbell spake the following on 8/16/2006 1:20 PM:
> Decided to make an intelligent statement this time:
> One thing I did find to lower my load average, though, was MimeDefang in
> a look-ahead environment.
> Before installing MimeDefang,  I was receiving about 25K messages a day
> per server. Most of those were secondary MX relays, that is, mail sent
> to the secondary MX by spammers, and then relayed to the primary MX or
> mail store. I just use the look-ahead function in MD, nothing else. The
> load average was slowly climbing into the 8+ range and higher as a norm.
> After the install, my message count dropped to around 10K a day, and the
> load average dropped to around 2-3 as a norm. It still shoots up once in
> a while, but nothing like before MD.
> Obviously, running MD will add overhead, but the drop of about 60%
> emails needing to be scanned more than made up for that. I then was
> better able to detect more hosts/IP to add to my MTA access file, which
> made things even better.
> Another thing to mention is that before and after, mail ran smoothly. It
> just took a little bit longer before installing MD as there were always
> more processes (sendmail) trying to deliver DSN mail and the likes.
> This is not an answer for all systems - it's just that I use my MXs in a
> bazaar way (I think). My primary MX for one domain is a secondary MX for
> another domain. The primaries hold the mailboxes for their domain.
> No smiley face statements here.
That is how I have been doing it. My PHB's will only spring for a single T-1
line to each site, so to get some decent fallback I had to do it that way.
Doesn't make much sense to put your secondary on the same end of a failure.
I was looking at milter-ahead until it stopped being free.
I have been looking for a clear howto for MD to do just what you have. Do you
have a good example or link to one?
I don't want MD to do anything except the look-ahead.

MailScanner is like deodorant...
You hope everybody uses it, and
you notice quickly if they don't!!!!

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