Multiple Copies of Emails

I upgraded two systems to Snow Leopard. Both systems have same mail accounts configured... and only one POP account on one system was experiencing duplicate email issue. The difference between the two systems is the Macbook Pro is 32-bit while the iMac is 64-bit. Although the kernel is 32-bit on both... Mail application runs 64-bit by default on the 64-bit capable system. I have since selected to run Mail in 32-bit mode on the iMac... and since then have not had any more duplicate emails (it's been over a week now).

Since following Ernie's suggestion to delete MessageUidsAlreadyDownloaded3, the problem has cleared up for me. For those of you still encountering the problem and who haven't tried his suggestion, please give it a shot. The details are posted in Ernie's reply on page 1 of this thread.

For those of you who have tried his suggestion and are still having problems, I commiserate.

Hey, out of the blue my inbox is being populated by duplicate copies of every email on the server.. I'm pretty sure this just started happening after the last Time Machine backup. This configuration has been stable for a few weeks so I can't think of anything else would trigger it. Only solution I can see is wait for them all to be duplicated then delete them. BTW this is a POP account.

Message was edited by: honkfink

I am running 64bit on my system and my mail app is 32bit. I haven't had this issue since then. It's been almost a week now. Not sure if this is the issue or not.

If it was a Time Machine Issue, then I would be interested to know, out of the people here having the problem, are you using time machine?

If so, then I would think you can Open Time Machine Preferences and exclude the MessageUidsAlreadyDownloaded3 file from backing up. If this were the case, then the issue would not replicate itself.

If someone that's having this issue responds and says they are not using time machine, then we know it's not a time machine issue.

Anyone??

Yes, I use Time Machine, but I think people are putting too much into MessageUidsAlreadyDownloaded3 being the root of this problem, as me and others are having this problem with IMAP accounts, where this is not applicable.

I'm not disputing it seems to help fix the problem (for POP users), but lets not get distracted from finding the cause otherwise it's probably just going to pop (no pun intended) up again in the future

Well it's strange for sure. I have about 10 accounts. I converted half of them to IMAP and not one of them have this problem, ONLY my POP3 accounts. Obviously, others are having an issue with POP3. But so far, since running in 32bit mode, I haven't had the issue duplicate itself (yet).

I also have not had this issue since switching to 32-bit Mail 5 days ago.

Just out of curiosity, is there anyone here who has had this issue who does NOT use Time Machine?

I think we have a breakthrough here! I am also using Time Machine, and have switched my Mail to 32-bit mode. Time Machine has been having issues, so I ran Disk Utility to try to repair with no luck, then I disabled Time Machine. During the time (about 2 weeks) that Time Machine was disabled, the replication issue went away. I then deleted the back-up files from the Time Capsule and re-enabled Time Machine. Now, the replication issue has returned. I am starting to beleive that this is surely related to using Snow Leopoard and Time Machine.

at this point I'm going to think that Time Machine, during some stage of backup, prevents access to MessageUidsAlreadyDownloaded3 during an exclusive lock and Mail is forced to redownload all the stuff if it's checking mail at the same time.

When you reinstituted Time Machine, was your mail still in 32bit mode?

I have been using Time Machine with Snow Leopard. I have three POP accounts and one IMAP account. The duplicating E-mail was a recurring problem a few weeks ago, but not with all of the accounts. Since no one seemed to be able to come up with I definitive fix, I have done nothing to my settings or preferences. The problem appears to have gone away on its own, as I haven't had a duplicate E-mail in almost two weeks. I'm just keeping my fingers crossed until Apple releases an update.

I'm running two tests:

Mail.app in 64-bit mode, Time Machine enabled, Mail set to check for new mail every minute, all working accounts disconnected, leaving only the problematic POP3 active.

1) trying running some manual TM backups while hitting get mail to see if the lock kicks in and duplicate email is downloaded
2) trying leaving Mail alone since it's checking every minute and running backups with time machine to see if they collide

This can explain the absolute randomness of this bug; it's a dual test since the faulty code may be in the auto-check routine but not in the check mail manually routine.

If anyone have some time to test this setup we can report our findings to apple.

YEs. Mail is still in 32-bit mode

Gregory Miller3 wrote:
I think we have a breakthrough here! I am also using Time Machine, and have switched my Mail to 32-bit mode. Time Machine has been having issues, so I ran Disk Utility to try to repair with no luck, then I disabled Time Machine. During the time (about 2 weeks) that Time Machine was disabled, the replication issue went away. I then deleted the back-up files from the Time Capsule and re-enabled Time Machine. Now, the replication issue has returned. I am starting to beleive that this is surely related to using Snow Leopoard and Time Machine.

Don't like to throw a spanner in the works, but whilst I do use Time Machine, I first experienced this problem (MobileMe - IMAP only) on my laptop whilst I was away, and my laptop does not have Time Machine active. Sorry!

Interesting. I have two laptops and one desktop backing up to my Time Machine, all running Snow Leopard. But the duplication problem only happened on my desktop. So far my laptops have been immune.