In my project I use ExchangeClient 2003 to synchronize incoming email. I have instructed the end-user to create a special folder in Exchange; all mail dragged to this folder will be synchronised. This is for purely procedural purposes and not technical: not all incoming email should be synched with Mendix and this manual procedure makes the end-user think twice about which mails to synch and which not. In some occasions the mail dragged to this special folder is synched twice. The pattern I have established so far deals with the LastSynch timestamp. Suppose an email was received but not dragged to the special folder. The synch microflow runs (it is scheduled to run every 15 minutes) and synchs all mail in the special folder with a received-timestamp younger than the LastSynch timestamp. Now, after this run the end-user decides that an email that was received earlier (so before the last run) should be synched after all and drags the mail to the special folder. This mail is synched twice: once the first time the synch microflow is run and a second time the next time the synch flow runs. It is not synched a third time. In a timeline this reads like this: Mail A received 11:40 but not dragged to special folder Mail B received 11:41 and dragged to special folder Synch flow runs 11:45 and synchs mail B Mail A is dragged to special folder at 11:50 Synch flow runs 12:00 and synchs mail A Synch flow runs 12:15 and synchs mail A again How to avoid this behavior?
I don't know, it seems like a bug so if you send in a ticket with a detailed case on how to reproduce this someone might be able to have a look at what's going on. You can also set debug mode in the advanced tab and another tab will appear in your my account form with object ids. Maybe the (difference in?) ids will show you something.
That said, if you can get your customer to upgrade to Exchange 2007 or up, that's an even better option. Support for web access and synchronization is not nearly as good in Exchange 2000/2003 as in later versions which use web services.