Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Cisco ASA 5500 SMTP return on source (nat'ed) IP

We have a number of static PAT as well as policy NAT pointing services from servers and loadbalancers to the outside world on specific ports. In this case, our Postfix Mail server is accepting inbound connections fine, and sending out fine - however.

We are experiencing a number bounces from certain providers due to a SMTP X-Source-Ip being the outside interface of the ASA, thus marked as SPAM. Outbound SMTP traffic needs to returning on SMTP as the originating mapped PAT.

The current config is using mostly policy NAT w/ object groups, and is being trimmed as services and hosts get decommed (objects were imported from a diff FW). I have also tested straight static PAT for SMTP to avoid policy NAT all together. Have also tried w/o 2nd global & nat commands, and have had no luck with either configuration.

Current running config:

Running config attached, with message text.

Open to ANY help on this one.


New Member

Re: Cisco ASA 5500 SMTP return on source (nat'ed) IP

Apologies, I posted this in the wrong forum, as it is not a VPN issue. I have posted this in Sec->FW.