Error when using IMAP through Frontend.

Hi all!

I've a NLB frontend-backend Cluster exchange topology.

Im trying to configure IMAP accounts to connect to the frontend which will forward it to the backend.

It doesnt work. Cant authenticate. I've enabled maximum IMAP logging and it appears this events:
- IMAP4SVC - Authentication - 1011 (Authentication attempt from <IP>  to <EMAIL> has failed with error 0x3b.)
- IMAP4SVC - Connection - 1016 (IMAP4 proxy connection to PROEXC00.bilbokoudala.lan for bilbokoudala/jsomoza (mailbox jsomoza) failed with error 0x3b.)

If i configure the account to connect directly to the backend, it works.

Any idea?

Who is Participating?
ikerasdConnect With a Mentor Author Commented:
The problem was with the antimalware appliance not working correctly with the IMAP protocol.
ikerasdAuthor Commented:

Forgot to say that other that appears (on the IMAP logs) is:
      An unexpected network error occurred.

I think i've everything i need open on firewall.

And Outlook Express also says:

   Nombre de usuario: bilbokoudala\jsomoza\jsomoza
   Protocolo: IMAP
   Puerto: 143
   Seguridad (SSL): 0
   Código: 800cccd1

But this is a general login error.
LegendZMPrincipal Security ArchitectCommented:
The Front end server should be where SSL is set up for POP3/IMAP.  It should not be
set on the Backend server. Verify that the POP3 and IMAP services
are enabled on both servers they're disabled by default.
This was a useful question that accurately reflected and resolved my problem. Moreover, Experts Exchange was the ONLY site that had a solution.
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