Wednesday, March 11, 2009

SOLVED: Blackberry Internet Service (BIS duplicate messages from Exchange

A number of my users have been reporting duplicate messages on their Blackberry handhelds when we reconfigured them to use our shiny new Exchange 2007 Servers. After some digging, a message was being re-delivered to the handheld every time the message was A.) Marked Read, B.) Replied to, C.) Found in a search. This occurs only with Blackberry Internet Service (BIS) users connecting to the Exchange server with IMAP.

As it turns out, Exchange is changing the IMAP message ID every time one of the above actions occurs*. This causes RIM to see the message as new and re-transmit it to the handheld.

The options to fix it are..

Switch BIS to POP3 instead of IMAP. But then deleted items sync won't work.
Switch to Blackberry Enterprise Server. $5k in software fees, more depending on your user count.
Switch BIS to OWA..

That last option is the most promising. Unfortunately, with Exchange 2007 and forms based OWA authentication (the default), the normal url doesn't work. Neither does

What does work... the magic bullet for BIS+OWA on Exchange 2007 is..

I have not found this tidbit on any forums or documentation, and I really hope it helps someone.

Good Luck,

* Constructive criticism for Microsoft. You stupid cod-flogging idiots. Why in the name of potato would you do such a thing?! Did you even _look_ at the RFC? This is what IMAP flags are designed to do. Please, please fix this, print the RFC and use it to flagellate the committee that designed this AND the committee that approved it.


bondsan said...

Hey there, thanks heaps for the helpful article. Just in case you need to put this through a linux firewall and are using ssl;

allow the port for https connection to owa, then in the blackberry setup enter:

seemed to be the last step with exchange 2007 and owa access via blackberry.

Anonymous said...

None of these 2 suggestions above worked for BIS integration with OWA. We use forms-based authentication and https for OWA.
Do you by any chance have other suggestions?
Thank you in advance,

Anonymous said...

This article was the answer to all my challenges. I did have to make two little changes.

I can't thank you enough! You are a rock star!!!

Anonymous said...

This is the only article that has been very helpful which actually solved my duplicate emails when using IMAP. I'm on MS Outlook (Office 365) with a blackberry 9930 BIS account.

Thanks so much!!!