Mailman 2.1.5-10.FC2 Problem; Probably sendmail-related

[Robert L Cochran]

I have a server box running Fedora Core 2 that has been just sitting 
there, dutifully working away, for a long while now. I haven't updated 
it at all since the 2.6.10-1.771_FC2 kernel, and that was a long time ago!

The server runs:

DNS via bind 9.2.3-13
sendmail 8.12.11-4.6
mailman 2.1.5-10.fc2

I have two low-volume mailing lists for my family. Suddenly, I am not 
getting any incoming emails from either list. Sending test emails to one 
of the list is showing they are being posted to the list archives, but I 
am not getting any posts by email suddenly.

Top is showing that sendmail is very active. There seems to be 3 or 4 
sendmail processes.

My hard drive light stays resolutely on, pretty much all the time. What 
on earth can be using the hard drive so heavily?

ssh connections into this server (from my internal network) take a 
terribly long time to establish. They take 30 seconds or so before I can 
get a shell prompt back over the wire. I just now ssh'ed into the 
server, then issued 'shutdown -r now', and it took more than 1 minute 
for the prompt to come back.

I'm wondering if sendmail has been compromised and is sending out huge 
numbers of outgoing email. Is there a way of finding out what sendmail 
is doing, to see if it is relaying mail for someone external to my network?

Can anyone suggest what might be the problem here? How can I rescue things?

Thanks

Bob Cochran
Greenbelt, Maryland, USA