Tuning MailScanner

Mariano Absatz mailscanner at LISTS.COM.AR
Thu May 22 22:33:19 IST 2003

El 22 May 2003 a las 16:10, mikea escribió:

> On Thu, May 22, 2003 at 04:40:59PM -0400, Gerry Doris wrote:
> > Sendmail is very efficient.  The real problems are the virus/spam scanning
> > especially the RBL checking.
I think most mail admins of large ISPs or companies heavy on e-mail wouldn't 
agree that "Sendmail is very efficient" (especially resource-wise)... 
however, the job of virus scanning and spam assessing (including RBL 
checking) is at least an order of magnitude larger...

Think about it, sendmail gets a message, possibly does a couple of dns 
checking (from domain, to domain) reads and scans the text until the first 
blank line and then it's done scanning. It has to move the files around and 
(in some cases) try to connect to another machine to deliver the message.

Now, the virus scanner has to thoroughly read (scan) much of the _content_ 
(body), the spam scanning does the same _again_, and (depending on your 
config), quite a few dns checks (various RBLs for the IP of the machine that 
connected to you, PLUS, the same RBLs for other IPs found in the "Received:" 

This is why, when I name MailScanner+SpamAssassin in the ZMailer list 
everybody shrugs and says you CAN'T do that (ZMailer _is_ actually quite 
efficient, and is usually in production in servers handling zillions of 
messages, usually in large farms dedicated exclusively to mail relaying)...

> >
> > Is the above correct?
> That's pretty much my take on it.
> Of course, tuning, even within those very broad guidelines, will be
> very much a matter of tweaking one thing at a time, hoping that it
> was the right thing, and wondering how much of the apparent change
> comes from the tweaked parameter and how much from changes in the
> characteristics of the processed mail.
> I've been doing much the same thing with mainframe operating systems
> since 1977, and it's still a black art. I used to have a black robe
> with start, moons, etc., on it, which I reserved for working on really
> bad problems, but my management disapproved. By the time I became
> management, the robe was gone. *sigh*
But now that you're management, you should get the robe back and you can even 
make lesser people to bow at you :-)

> --
> Mike Andrews
> mikea at mikea.ath.cx
> Tired old sysadmin since 1964
Man... and I considered myself old in the field... I was born in '65... maybe 
it's time I start bowing, master...

Mariano Absatz
El Baby
I thought I wanted a career, turns out I just wanted pay checks.

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