The company I work for is having this issue with Exchange 2007. We have a proprietary email client that does regular checks for new messages. Some users also have blackberrys and other devices that they use to check their email (using BIS). I find that there are some actions (which I can't define 100% but appear to be related to replying/forwarding or messages) that cause the email to have it's UID changed to the next available UID. This causes a problem when our POP client does a UIDL request to the Exchange Server and the server gives the same message back as "new" and it makes it into the inbox despite already being in the inbox. I have thoroughly researched this problem and I have yet to be given a solution except "don't leave mail on the server" which is NOT a solution. Please let me know why the UIDs are changing and what Microsoft intends to do about it.

If you believe this to be a bug in the product, then you will need to open a support case rather than use the community support forum.I haven't ever seen this problem even for users who leave the message on the server. Do users also have the blackberry desktop software on their computers? Is it possible the changes that makes to the messages is part of the issue? does the problem occur for non-blackberry users as well?

This is happening for many users, a couple of users at my office, and alot of blackberry users overall: http://forums.crackberry.com/f2/receive-duplicate-email-bb-after-replying-outlook-18424/ http://forums.crackberry.com/f86/please-help-duplicate-e-mails-141765/ It may not be a bug. There could be a setting, or a registry hack that would turn this behavior off. For us it is happening to blackberry pop accounts (not imap), only when the message is replied to via outlook, not when replied to via the blackberry itself. Like so: Receive email (in outlook, and BB) reply via outlook > duplicate of original is resent to BB reply via BB > nothing, works like it should

We maxed out our BES server so we added a few users via IMAP. If outlook 2007 is closed then everything runs find. When outlook 2007 is opened.. We get dupicate email on the BB. And if any older email is opened.. a copy is sent to the BB also.

I have heard that it's Microsoft's Exchange server which is not following the IMAP standard. The UID should not change when replying, opening, etc an email on an IMAP standard email server. Since Microsoft is not following the IMAP standard, the Blackberry server sees all new UIDs as a new email and delivers them again. I'm not sure who is going to budge on this issue. Either Microsoft needs to start following the IMAP standard in Exchange, or BB needs to check for something other than just a new UID. Personally, as much as I think Microsoft should adapt to the standard, I wish RIM would just add in something to their email poller, which would probably be faster to implement. I have to stuff my phone away during the time i'm at work so I don't see all the new emails I think I'm getting. It really drives me nuts.

For a full list of RFCs supported by Exchange 2007 please see following http://technet.microsoft.com/en-us/library/cc540463(EXCHG.80).aspx.HTH