Why can my Blackberry users not access their accounts via POP or WebMail?

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The Blackberry Internet Service has recently changed its behavior by permanently connecting to IMAP accounts using the IMAP IDLE facility. This has the effect of permanently locking out other protocols from accessing any message store held open by the Blackberry service.


GMS is an extremely robust solution and was developed with the security and integrity of messages in mind at all times. Consequently we use file locking to ensure that a message store can not be updated under the feet of another connection, particularly when using another protocol. The IMAP protocol is designed from the ground up to support multiple access and provides means of updating all connected clients when a message store is updated. Unfortunately this is not true of other protocols such as POP, so there is no way of flagging a change made by a POP client to an IMAP client and vice versa.

As you can imagine this leaves us with a bit of an issue as to how to work round this problem without insisting either all connections are IMAP, or that the IMAP IDLE command is disabled (which is required for Collaboration in any case).

We have come up with a solution whereby when a connection comes in from a POP client, we simply disconnect (nicely) any IMAP connections to the same message store that are in the IDLE state. These IMAP connections will simply try and reconnect again, and no harm done. Internal testing shows that this works and does not impact on the performance of BIS connections. This has also been confirmed by customers.

WebMail users can also be similarly affected to POP users therfore an update for the WWW service is also provided.

Note: This feature is OFF by default and you need to set a system level variable to enable it:


These files are only valid for build 3664 (v15.01) of GMS
From build 3689 (v15.02) onwards, these fixes are included in the main codebase of GMS so there is no requirement to patch your existing files.

You will however need to activate this feature by enabling the variable mentioned above.


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Keywords:BLackberry Internet Service RIM BIS POP WebMail

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