How to check if your SMTP server is an open relay

If you’re setting up a Mail server, one of the most important tasks you need to do is ensure it’s not an open relay. Open relay means anyone can send out emails using the Mail Server without any authentication. If your SMTP server is an open relay, you are most likely to be blacklisted by all major spam lists. So, here’s how you can check whether your SMTP server is an open relay: telnet...

October 23rd, 2010 by Akhthar Parvez