POP3 RETR and 0x800CCC90 errors - new information

[peter.zagar]

Hello everyone,

I have been recently following the developments regarding the nasty POP3 bug which causes Thunderbird and Outlook 2007 to fail at mail retrieval via POP3 and possibly also via IMAP.

After extensive testing today I found a new clue which might bring us closer to a solution.

Untangle:
Bridge mode.
All modules ON, including Spam, Phish and AV. Protocol checking ON.

Network Layout:
External Mail server - Cisco ASA - Untangle - Internal network with clients

Email Server:
Communigate

Email Client Facts:
Outlook 2007 - cannot retrieve mail
Outlook 2003 - retrieves mail after slight delay
Thunderbird - cannot retrieve mail, but sees the number of messages on the server

Error messages in question:
Outlook 2007 - Task 'receiving user@domain.com ' reported error (0x800CCC90): 'The mail server (POP3), has found an internal error
Thunderbird - The RETR command did not succeed. Error retrieving a message.

What i have found out is, that there is a delay of about 2-3 seconds, when Untangle modules are processing messages.

This causes Outlook 2007 and Thinderbird to fail. Thunderbird gives RETR error instantly.

So I tried to connect to server via telnet. I logged in, listed messages on server, then tried to retrieve a message using a RETR command.
I noticed that, when Untangle modules in question are turned OFF, ie. the traffic is not processed, messages are retrieved instantly. When the modules are turned ON, the retrieval of message is delayed by about 2-3 seconds.
The message still gets normally retrieved, after the delay. All the headers and text in the message is identical to the one when not processed.

I tried to solve this by setting the email clients to have more tolerance to this delay but I could not solve it neither in Outlook 2007 nor in Thunderbird.

Regards,

Peter

[sky-knight]

All that said, I have outlook 2007 clients working flawlessly without any adjustments.

As long as you have the AV module enabled, there will be a 1-3 second delay for downloading each message as the message is scanned for viruses, not to mention the spam blocker as it tries to do its job. The delay is by design.

If the delay is too long, you may have a situation where your Untangle isn't powerful enough.

[peter.zagar]

Could you be more specific about your mail server, etc..
Is your mail server inside your local network?

[sky-knight]

I use Outlook 2007 here in my office. I connect to client servers externally, some over the inet, others over VPN. I have clients that have mail servers on their lans they connect to both locally and remote.

I've tested, smartormail, mailenable, exchange 2007/2003, postfix, and sendmail.

They all work fine.

I do know that the eavesdropping Untangle does can break things. So the question is, what mail server are YOU using, and where is it in YOUR chain. Something in that is causing an issue and you may just have the network that can provide the details to finally nail this one down.

[peter.zagar]

So the question is, what mail server are YOU using, and where is it in YOUR chain. Something in that is causing an issue and you may just have the network that can provide the details to finally nail this one down.

I've tried to include all the details in my original post above:

Network Layout:
External Mail server - Cisco ASA - Untangle - Internal network with clients

Email Server:
Communigate

I am lost here as I tried so many things to solve this, but nothing helped.

[peter.zagar]

Ok, I'm attaching logs from Outlook 2007 when receiving pop3.
Unt.log is created when the communication is going through Untangle.
NoUnt.log is created when Untangle is bypassed.

See the network scheme in original post.

[doubtintom]

My web host switched email servers last weekend, and I and a client of mine who has Untangle (both running 7.1 Debian boxes) started getting the RETR errors. I am running Thunderbird 3.0.1, he is using Thunderbird 2.0.0.23.

Old Server:
courier-imap-4.6.0-2

New Server
Dovecot 1.1.13

Only by turning off the spam, phish and virus blockers do the RETR errors stop and email comes through -- unscanned of course.

Is this enough information to further the analysis?

[RobertFranz]

My issue is that whenever I have the UT box enabled, connections to the exchange server from Outlook 2007 fail.

My configuration is like this:

Exchange server 07<-main colo Mikrotik<-vpn tunnel<-SMC gateway->Mikrotik->UT->XP->Outlook 07

I tried turning off all modules - results are unclear.

From one workstation, I am able to connect without issue after turning off modules and restarting Outlook.

On another, coming up from a cold boot, it's unable to connect to the exchange server.

This could be an interop issue, with my suspicion being Kaspersky.

Unfortunately, I ran out of time this morning for testing.

I'm going to do some further testing later today.

This *is* a UT issue, at least in that documentation should exist for common interop issues, and troubleshooting common network applications as they touch upon UT.

[doubtintom]

I gave data above about my web host, which had switched email serves (to dovecot), after which two Untangle servers accessing mail from the same web host started getting the RETR errors. I wound up switching our email accounts to IMAP to escape the RETRs.

I just learned that a few months ago my local ISP made a similar transition to dovecot, and immediately the RETR errors started showing up on my email address with that ISP. I hadn't made the connection at that time. So I've steered away from POP for the time being. But this information may help someone.

Old email server:
Qmail 2.6

New email server:
Dovecot 1.0.15

I just noticed though, maybe it has been since my 7.2 upgrade(?), the old ISP email account, which is still POP as the ISP doesn't offer IMAP, is no longer throwing RETR errors. Go figure. Hey, Untangle devs, did you fix something?