How to restrict email relaying?
 

I run a vps with multiple domains. I have been seeing email which appears to come from my domains, but I'm not sending it. If I restrict relaying would this fix the problem? If so, how do you restrict relaying?

TIA!

Relaying is when someone uses your SMTP server to send mail somewhere else. If whoever sent the emails didn't send them through your server then stopping relaying won't fix the problem. If they are sending them through your server then stopping (or restricting) relaying will help. Can you provide more info on your mail server please?

By the way, you might also look at http://www.openspf.org/. SPF is a way of preventing return-path address forgery.

HI,
add following in your
/etc/mail/mailertable for the domains which are on the vps
Also add the domain names in following file:

Still, you have to go for spf, drbl and so on to minimize spam which cant be stopped completely!

http://en.wikipedia.org/wiki/Open_mail_relay
http://en.wikipedia.org/wiki/SMTP-AUTH
http://en.wikipedia.org/wiki/Extended_SMTP
http://en.wikipedia.org/wiki/Sender_Policy_Framework
http://en.wikipedia.org/wiki/DNSBL

aniruddhas.com : Aniruddha

DKIM (DomainKeys Identified Mail) might help you on this also. DKIM signs every mail coming from your domain and thus being attested to legitimately coming from you. Sendmail has this already through dkim-milter which as well runs on Postfix that integrates with amavisd-new.

Also by providing my postfix mail with postgrey, amavisd-new, spamassassin and clamav, these sort of mails seems to be coming from my domain are getting blocked rightaway.

http://www.elandsys.com/resources/sendmail/dkim.html