Started getting the H:RPBL refused messages today. I have found that Reverse DNS is failing. I know why but do not know how to fix it. Here is the info:
PIX 515e firewall
Two SMTP domains are used on the same server: (I will use fake names and IP's)
- @mail1.com using external IP 22.214.171.124 NATed from 192.168.0.1
- @mail2.com using external IP 126.96.36.199 NATed from 192.168.0.2
- Both NATed IP's are on the same server.
PIX firewall External IP is 188.8.131.52
When @mail1.com users send an email, the header shows:
- Microsoft Mail Internet Headers Version 2.0 Received: from smtp.mail1.com ([184.108.40.206]) ...
Because it is showing and IP of 220.127.116.11 the Reverse DNS fails. It should have shown an IP of 18.104.22.168
The IP in the header is the external IP of the PIX firewall, not the proper external IP of the SMTP server. I can not find where I can set this. I assume it is in the NAT portion of the PIX.