sendmail disable relaying

[kholikt]

I have a server running sendmail. By default this server is relaying any mail from any server. I have found the spammer started to use this server to spam unsolicited email.

Is there anyway I can restrict only certain internal servers allowed to use this server to relay mail.

[Michael Tully · Accepted solution]

Hi,

Create a the file /etc/mail/Relayto, with entries for localhost and other machines you want to be able to relay to. Make sure your sendmail.cf file contains the line

F{RelayTo} /etc/mail/RelayTo

or whatever name you decide to give the file.

Have a look at this link for more info:
http://www.sendmail.org/antispam.html

This document also contains information
/usr/share/doc/sendmail8-8_delta.txt and
/usr/share/doc/sendmail8-9_delta.txt

HTH
-Michael

[kholikt]

Thanks for your advise. Just wondering which part of the sendmail.cf I should put in the line.

[Michael Tully]

Hi,

Depending on what OS version you've got
and what version of sendmail it is
actually included. I have a december 2001
patched system of HPUX 11 and it is
included. I don't think it really matters
that much, but I suggest you have it
before your existing smart mail relay variable.

-Michael