I'm rather perplexed on an issue. I have Exim3 running, and only 200
e-mail accounts. On a per-user basis, incoming e-mail will go through
procmail, and may go through spamassassin and/or sanitizer. Fairly simple.
Also have courier IMAP, IMAPS, POP and POPS on the machine, though I don't
think that comes into this. It also hosts some web sites, but they are
very low volume.
Since last Saturday, the system has slowed to a crawl, taking over a
minute to send an e-mail, if it doesn't time out. Seems to be independant
of the client (ie Squirrelmail on server, Outlook on client, whatever).
CPU has not dipped below 75% available, iptraf reports 50kbits/sec,
nothing strange in the ps list, ckrootkit says we're clean, etc...
I told exim not to do DNS lookups, but that seemed to have no effect. I
did have 20k frozen files in the queue, but got rid of them. Getting a lot
of spam and several attempts to use the server as a relay, but not enough
to make this happen.
Any suggestions on where to look now? Any help would be appreciated. The
box is pretty old and being replaced in March, but I have to keep the
clients happy between now and then.