My email server is sending out spams. No, they're not from us. How do I stop this? I'm not even sure what SMTP program we're running. We're running Redhat 6.1.

HELP!

And, yes, I don't know the first thing about Linux...

Run Linuxconf and in the senmail configuration module, choose enable relay control.

Go to the Anti-spam filter section and choose "reject by IP" and enter your network address. This should solve the problem.

We used to have the same problem until when i did this 2 days ago and we've not had the problem again hoping that it has been solved by this solution.

Great, thanks! Now, um, how do I test it to make sure that it worked?

When I chose "enable relay control" I could no longer send mail at all. Why is this? Any other ideas?

Check out /etc/mail/access

Add:

127.0.0.1 RELAY
.
.
.
owndomain.com RELAY

With sendmail,you could use /etc/mail/access to control the relay permission on your server(There is a good reference in http://www.sendmail.org/tips/relaying.html).

Also,you could set smtp auth in sendmail,however,it needs version above sendmail.8.10.I think that may be a more flexible solution.You could get info from http://www.sendmail.org/~ca/email/auth.html

Well this is completly out of subject here but the spam is very dangerous and must be stoped. In your /etc/mail/sendmail.cf

Add (under * OPTIONS *):

F{SpamDomains} /etc/spamdomains.txt
F{Spammers} /etc/spammers.txt

Scheck_mail
R<$={Spammers}> $#error $@ 4.7.1 $: "471 We Dont accept Spam here. BLOW ME bitch!"
R$={Spammers} $#error $@ 4.7.1 $: "471 We Dont Accept Spam Here. Dont make the admin Angry!"
#R$* $: $>3 $1
R$*<@$*$={SpamDomains}.>$* $#error $@ 4.7.1 $: "471 Sorry i dont accept Spam. FSCK OFF! or BL0W ME"
R$*<@$*$={SpamDomains}>$* $#error $@ 4.7.1 $: "471 Sorry i dont accept Spam. FSCK OFF! or BL0W ME"

With tabs! Sendmail reconizes the syntaxe via tabs I have also got a VERY nice spammers.text and spamdomains.txt if you want them just e-email me at @ oliver@nerdzland.com