duplicate email issue

[kollross]

We've been getting several reports of people when downloading email from a 3rd party client (outlook, outlookexpress for sure possible others) using pop they are receiving duplicates email messages in there inbox, sometimes 3-4 copies of the same email. I can view there email through the Zimbra webmail and the duplicates do not exist there. I'm wondering if there is some sort of caching issue somewhere somehow. Wondering if there was a known issue and if there was workaround for the issue. Again this is not widespread but we are starting to hear more and more reports about the problem.

[KevinH]

Is it only happen with POP? There is a MS KB article for Outlook clients.

http://support.microsoft.com/?kbid=885870

I quick google search shows that in general this is a common problem with POP clients especially over slow links. Are these folks on dial-up?

[kollross]

The majority of the cases were dialup however i know of a few that were on a cable connection. I read the previous link and will try that. Though I know this is not only limited to Outlook 2003 clients. Interesting thing about that microsoft article is it talk about the issue involving leaving messages on the server. They never really said anything if we disabled that option if that would fix the problem....hmmm.

[bobby]

there was a bug* in the server related to message counts that was crashing pop client connections, so some messages marked for deletion weren't getting deleted. it's fixed in the release due out soon (i.e. this week or so).

but you might also have a look at this about corrupted uidl dbs

* bug 4033: Sync caused NPE in Conversation.removeChild()

[kollross]

I dont believe this is a result of messages being deleted. These are new emails that are being checked for the first time.

[kollross]

I just got off the phone with someone who is using IMAP whom is receiving the same email (3 to 4) times over the course of the day. I looked in his Webmail and see no duplicates present prior to him deleting the duplicates. I've heard from several of the techs about the same issue. I've now seen this problem with both pop and imap, and they are using both broadband and dialup connections.

[KevinH]

Are there any exceptions or errors in your logs? Check both /opt/zimbra/log/zimbra.log and /opt/zimbra/tomcat/logs/catalina.out

[bobby]

you can also turn on, for example, extra pop3 logging. then with a little help from rfc 1939, you can see if the client and server are issuing appropriate commands, and if the server is choking.

on the server:

In the file /opt/zimbra/conf/log4j.properties, find this line:
log4j.logger.zimbra=ERROR,SYSLOG

and add this line right below it:
log4j.logger.zimbra.pop=DEBUG

save that, and run
tomcat stop; tomcat start

this will log pop3 transactions in /opt/zimbra/log/zimbra.log


on the client:

for outlook express:
check the box next to Mail in Tools menu/Options.../Maintenance tab/Troubleshooting

the log will be here:
C:\Documents and Settings\<user name>Local Settings\Application Data\Identities\{<LONG-STRING-OF-DIGITS>}\Microsoft\Outlook Express\pop3.log

for outlook:
ms help

[kollross]

There were no errors in either of the logs for the one specific this particular user
/opt/zimbra/log/zimbra.log and /opt/zimbra/tomcat/logs/catalina.out

[bobby]

if you turn on DEBUG level logging in /opt/zimbra/conf/log4j.properties for pop and imap, lots more info will show up in /opt/zimbra/log/zimbra.log

log4j.logger.zimbra.pop=DEBUG
log4j.logger.zimbra.imap=DEBUG