ASA - Inspect ESMTP

Answered Question
May 28th, 2010

I am working with an ASA 5520 with a SPAM appliance located within the DMZ.  Not all smtp connections are being corrupted by the inspect esmtp setting, just a few.  It was discovered that those few sites that are connecting to the SPAM appliance traverse 2 additional firewalls (1 ASA and 1 PIX), *before* their smtp traffic hits the Internet to continue on to our DMZ.

Why would this be the case?  Is it due to passing through two additional firewalls that may be adjusting the headers (static NAT, etc.)?

If we are not comfortable turning off the inspect esmtp setting, is it possible to write a specific policy that would include these few sites MX records?  If so, how might that be done?

Thanks,

Jim

I have this problem too.
0 votes
Correct Answer by pkampana about 3 years 10 months ago

You could create an access list

that matches specific server ip addresses and put it under the policy map and inspect esmtp on it

------------

access-l esmtp-acl deny tcp any eq 25

access-l esmtp-acl perm tcp any any eq 25

class-m esmtp-cm

  match access-l esmtp-acl

policy-map globasl_policy

  class espmtp-cm

     inspect esmtp

------------

I hope it helps.

PK

  • 1
  • 2
  • 3
  • 4
  • 5
Average Rating: 5 (1 ratings)
Correct Answer
pkampana Fri, 05/28/2010 - 17:48

You could create an access list

that matches specific server ip addresses and put it under the policy map and inspect esmtp on it

------------

access-l esmtp-acl deny tcp any eq 25

access-l esmtp-acl perm tcp any any eq 25

class-m esmtp-cm

  match access-l esmtp-acl

policy-map globasl_policy

  class espmtp-cm

     inspect esmtp

------------

I hope it helps.

PK

Actions

Login or Register to take actions

This Discussion

Posted May 28, 2010 at 4:05 AM
Stats:
Replies:2 Avg. Rating:5
Views:950 Votes:0
Shares:0
Tags: No tags.

Discussions Leaderboard

Rank Username Points
1 7,861
2 6,140
3 3,170
4 1,473
5 1,446