i have an unusual problem here... maybe one of you has had to deal with it before. i'll describe my situation as well as my problem... you may be able to lead me to a solution?
i have sendmail in it's background daemon mode accepting smtp connections. all emails are sent out using my isp's smtp server to simplify things. i also have fetchmail getting users' emails from isp's pop server and sending them through sendmail to the local user accounts. sounds simple enough.. i think so anyway. it all works beautifully, no problems sometimes for days. then one day sendmail has trouble responding. example:
# telnet localhost 25
says hello to me
MAIL FROM: firstname.lastname@example.org
HUGE delay... don't know how long... then eventually
email@example.com <Sender OK>
then bla blabla.
this delay wasn't there before.
i then go to linuxconf and simply access the sendmail configuration section. press accept and it tells me the sendmail.cf isn't up to date... update it.. restart sendmail then everything's great for a little while again.
strange no? sometimes sendmail hasn't even had any emails to send before it goes wierd again. has anyone encountered this problem before?
i'd appreciate any ideas, thanks!
I know this isn't helping, but have you considered running postfix instead? Mucho simpler to setup than sendmail. I've not had a problem like that one... Do you think your problem is related to the slowness issue you posted about earlier?
<i>I used to have a girl, but then I got my CS degree...</i>
no... it's definately something new....
all requests come through at the speed they should (instantaneously) this is different.... mostly cause it's intermittant. it's not a handshaking delay, more of a name lookup delay.. but it shouldn't exist because it's so easily corrected and then everything works perfectly until the next time it goes iffy...
Well, linuxconf doesn't change sendmail.cf, you don't change any entry (only if somebody else changed it). This problem can have many different reasons and you didn't provide necessary information:
1) it is always good to write a version, here a version of sendmail you use - some versions can have some problems, I don't know which one you run
2) did you check the possibility your system was attacked by for example DoS attack? (you don't write if it is on fixed or dialed connection)
3) how many sendmail processes were running at time you found problems? Which uptime machine had? Trying to send many mails to unresolvable domains you can run out of resources, which restart of service will solve (for a while)
Don't use Linuxconf for configuring anything. Mostly not sendmail, apache, ftp and samba. You never know, what it does to poor config files. To configure sendmail, use sendmail.mc pre-configuration file, it is easy to use. Make sure it does what it has to do, nothing more, nothing less.