I have a few users, who are also Blackberry users, that occasionally have duplicate emails generated from their "mailbox". I put mailbox in quotes because I'm not exactly sure where the duplicates are created.
One of these users is in non-cached mode, and the other is in cached mode, and both experience the problem. In fact, the non-cached mode user was originally experiencing the problem while in cached mode, and I made the switch a few weeks ago to attempt to solve the problem. Today I discovered the issue still exists.
I'm not sure if the fact that they are blackberry users could be causing the problem at all. I don't see how, but felt I should mention it anyway.
Does anyone have ideas on how I might begin to troubleshoot this? I can see in the non-cached user's mailbox "Sent Items" that the message was sent only once. I confirmed the message does not state that there was a conflict and in fact that makes sense because they are in non-cached mode.
On the server, we have a mail journaling feature turned on for our third-party mail archiving system, and I can see that that system sees two sent messages. And likewise, the recipient does in fact have two messages in their inbox with consecutive message IDs
It would seem to me that the duplicates are generated on the client, but is there a way to tell for sure?