Protect Sendmail Server from Open Relay.

nishith · 12-10-2008, 05:07 AM

Using Sendmail Version "8.14.1-2" in Fedora 7,i386 build.

Now, it is working fine for send/receive mails.I have implemented below policies & tools on sendmail.

MailScanner
Spamassassin
ClamAV

Now,All above tools are in in customization. & My problem is "How to protect mail server from Open Relay"?

Mean to say,if someone is trying to make "telnet <mail.server> 25 IP" connection, the outsider will get rejected.

So,someone please tell me the perfect steps for such "Open Relay Protection".

Waiting.
Nishith.

unSpawn · 12-10-2008, 06:53 AM

Quote:

Originally Posted by nishith

How to protect mail server from Open Relay

Add FQDN's and IP addresses in /etc/mail/access like "1.2.3.4 RELAY" then rebuild the databases (restarting Sendmail might do that for you, depending on script). Then search for HOWTO's concerning "SMTP auth".