On Wed, 2004-08-25 at 17:41, Lucas Albers wrote:
> I had good luck with a pass-through server.
> I'm using a 3ghz, 2g ram system, that handles only about 8k mail a day for
> around 500 users.
> It bogs down even then, because of the incredible huge stream of spam
> coming in day or night.
> It just maxes out on number of concurrent connections, I set my limit to
> 20 concurrent.
> I think ram is the most important item and a pre-forked spamd or
> mimedefang preforked spamassassin process.
> The nice thing about relays is you can scale linearly by just adding in
> more machines.
> I'll add in another pass-through machine when I finally configure it so
> the mail can only go through the relay's to hit the internal mail.
>
> I've found even my temporary solutions turn into production solutions, and
> I'm stuck with whatever hardware I originally used.
> So start with decent hardware to begin with...not great...but decent.
> --Luke
>
> Ronald I. Nutter said:
> > I am using it as a passthru to my two on campus mail servers that have
> > the mail accounts for staff/faculty/students. That is one of the
> > reasons that I picked the Scott Henderson guide to build my system
> > around so I wouldn't have to migrate all the accounts to it. I am going
> > to add some more memory for general principle to keep it from having to
> > kick into the swap file. Once administration likes what it is doing, I
> > will probably be given the money to put it on a system with more
> > processor and memory.
The secret to reducing cpu load is rejecting messages based on the
various RBLs (if your policy allows it). I consult for a local ISP.
They have a pass-thru filter box running postfix+amavisd+clamav+
spamassassin. It handles 30000-35000 messages a day. 25-30000 are
rejected by postfix and the rbls; 500 a day are viruses caught by
clamav; 5800/day are spam tagged by spamassassin; with about 2800/day
passed on to the mail server with user mailboxes. That's an
average of 8.7% non-spam, non-virus, email over the last 60 days.
The hardware is dual 400 MHz Xeons with 1G of RAM. Not your fastest
box, but the load average is 0.4 - 0.5. With a single Xeon, it was
running an la of 2.3 - 2.5 and tended to get bogged down when a storm
of spam hit.
-Bill
