[PLUG] Email server performance

[Michael Rasmussen]

Robert Anderson wrote:
> Imap access does touch the maillogs and the size of the logs does not
> appear to have an effect of performance. This machine is the incoming
> and outgoing mailserver as well as the mailhost, where user mailboxes
> reside and are accessed via pop and imap. We also have spamassassin
> running. Each uses account is configured to run all incoming mail
> through spamd. I am seeing several spamd processes that have resident
> size of 12-18mb. Could this be causing all the IO? I think the max
> email size is currently set to something huge like 25mb or so.

Do you have an idea of your spam rate?  And in the "I'm an idiot"
department, you may recall that I've posted before on the ill-effects
of virus checking on incoming emails.  

This would be easy to verify.  Run top, wait for the system to slow
down and see if spamd is a frequent entry in the Top 5 list of 
active processes.  That certainly was the case when my system would
slow to a crawl.  

You didn't mention your mail server, sendmail or postfix? In either case
if this line of reasoning is correct you need to enable whichever to 
recognize legitimate addresses on your system and reject mail for 
accounts that don't exist.  

If you're running postfix I can also provide a half baked utility to 
munge iptables when a spammer tries to send email to randomly made 
up addresses at your company. 

-- 
    Michael Rasmussen, Portland Oregon  
  Be appropriate && Follow your curiosity
 http://meme.patch.com/memes/BicycleRiding
   Get Fixed:  http://www.dampfixie.org
  The fortune cookie says:
Zounds!  I was never so bethumped with words
since I first called my brother's father dad.
		-- William Shakespeare, "Kind John"