Solved: ESMTP ASA 7.2

rasoftware · ‎06-01-2010

I have an unusual problem where ESMTP is working to some but not other Message Labs servers.

I see this error on the ASA - ESMTP Classification: Dropped connection for ESMTP Request from inside:

Questions is - do I need ESMTP inspect on the firewall?

I have lowered the settings to "low" security for now too see if this helps.

Thanks

Jennifer Halim · ‎06-01-2010

Yes, pls go ahead and turn it off.

View solution in original post

Jennifer Halim · ‎06-01-2010

Here is exactly what "inpsect esmtp" does for your information:

http://www.cisco.com/en/US/docs/security/asa/asa80/command/reference/i2.html#wp1719425

Basically in a nutshell, "inspect esmtp" restricts the smtp protocol to only the 15 SMTP commands, providing a more strict inspection on that protocol.

However, since all the mails will be inspected by MessageLabs, it should already been taken care off as Message Labs is solely providing email security.

Hope that answers your question.

rasoftware · ‎06-01-2010

Yes - so this can be turned off? All mail flows to and from Message Labs without external access.

I recall a few year back have to disable it on a PIX as it stopped Exchange servers talking to others correctly across the a VPN.

Jennifer Halim · ‎06-01-2010

Yes, pls go ahead and turn it off.