Just set up any email client on the host system to connect with IMAP to 127.0.0.1 and see what happens.

From a networking perspective it will make no difference what folder a message being requested by IMAP is in. Can you open the new messages (.CNM files) in the mailbox with for instance Notepad or are the files corrupt?

/Rolf 

Mercury server stopped working about 3 days ago and I've exhausted my meager knowledge of things to try to get it back working again. I can look at mail sent before that time, but all new mail never gets delivered. Below is what I see in the log files. If there is anything else I can post to help resolve this, let me know. I am going to the site to look at this system from the drivers chair, so I will check back for any suggestions on what to try in about an hour and a half from post time. Thanks in advance for your help. PS: The system is set up for imap mail, not pop. Sending is done via the service providers smtp server and that works.

 CORE log file stopped three days ago---when mail stopped working.

MercuryS log file has entries like the following
------------------------------------------------
T 20100627 002449 4c251154 Connection from 128.128.76.87
T 20100627 002449 4c251154 EHLO postal1.whoi.edu
T 20100627 002449 4c251154 MAIL FROM:<rkatcher@whoi.edu>
E 20100627 002449 4c251154 Unexpected abort talking to 128.128.76.87
T 20100627 003449 4c251155 Connection from 128.128.76.87
T 20100627 003449 4c251155 EHLO postal1.whoi.edu
T 20100627 003449 4c251155 MAIL FROM:<rkatcher@whoi.edu>
E 20100627 003449 4c251155 Unexpected abort talking to 128.128.76.87

MercuryI log file typical entry as follows
------------------------------------------
Connection from 67.223.66.242, Sun Jun 27 00:00:58 2010
edangelo at 67.223.66.242: 0 sec. elapsed, connection closed Sun Jun 27 00:00:58 2010
Connection from 67.223.91.198, Sun Jun 27 00:01:41 2010
pdangelo at 67.223.91.198: 0 sec. elapsed, connection closed Sun Jun 27 00:01:41 2010

I assume you already did the most obvious things, like restarting Mercury and the computer it's running on, and checking that there is sufficient free space on the disk that Mercury uses for it's queue and scratch directories. As connections can be made, at least briefly, it's probably not a firewall or ISP block issue. Did you by any chance make some kind of update to your antivirus program or any other program that might intercept network traffic 3 days ago?

/Rolf 

Rolf...The system has been restarted several times. The system is not under my immediate control, so I can't say absolutely nothing has changed, but I don't see anything obvious. I can telnet to port 143 from an external site so the port definitely seems to be open. Is there any debug logging option I can turn on to get more information about what exactly is happening?

I turned on session logging for the imap server. It created 4 files in quick succession. The first one has a bunch of stuff that looks OK, then ends with the message "socket write error 10053 econnaborted". All the other files appear to my eye to have no errors. I found a link that says this is caused by anti-virus software, so I disabled all the AV software and send another email. Still nothing arrives. I guess I will go back and turn on session logging again in this mode and see if anything changed.

Something appears to be happening at networking level rather than in Mercury itself that break connections. Antivirus programs are known to cause this kind of behavior, but it could be several other things as well. It's most likely to be on the system that runs Mercury, but it could be on some other device along the route. Try to do some more testing to narrow it down (like connecting with IMAP from somewhere in the same LAN to bypass Internet connection devices, or from the same computer to 127.0.0.1 to see if it will be the same on loopback).

/Rolf 

Rolf...I'm not clear on what you are suggesting. I can connect to the mail server both from the same LAN and from an external site. When I do this, I can read the messages that have been received. It's just that it will not receive any new messages. I can telnet to the system using port 143. If there is some other test you feel I should run, please give details. I'm not too knowledgeable about this so I will need details. Thanks....

Messages that have been received earlier are presumably cached by the email client, so I would assume that the IMAP connection in fact always fails when you try to get a message from the server. If you try to connect from different places (from within the LAN, from the same computer) it might be possible to draw some conclusions about where to look for the problem.

/Rolf 

Rolf...I am certain that I am able to access old emails and that they are not cached. There is a large archive folder that I am positive the current system, which is on a completely external LAN, has never accessed. When I connect to the mercury server, I can see it downloading the headers and, if I pick a random message from the folder, I can see the entire message. I tried to set up connecting from the computer hosting the mail server, but I guess I don't know how to configure it. Do I need to configure both client and server, or can I just configure the client on the host system?

[quote user="rkatcher"]I turned on session logging for the imap server. It created 4 files in quick succession. The first one has a bunch of stuff that looks OK, then ends with the message "socket write error 10053 econnaborted".[/quote]

Did you look here http://community.pmail.com/forums/thread/1546.aspx ?