Put this together from a posting I made to the MAPI-L list and a couple cases I worked recently:
The problem is with MAPI store providers that just don't work when loaded under Outlook 2003. The developers of the providers, when they contact us, are usually convinced the problem is a bug in Outlook 2003 since the providers “worked perfectly” under Outlook XP. My experience though, is that the problem is that Outlook 2003 demands so much more of the MAPI spec than previous versions of Outlook that bugs which have always been in these providers are now exposed. What's very interesting though is that I'm seeing the same bugs over and over in these providers. I hope to highlight the source of these bugs and offer some ideas on how to correct them.
There is a book which is very much coveted in the MAPI development community: Inside MAPI. One of the samples in this book is MSLMS, the Microsoft Sample Local Message Store. For what it is, sample code demonstrating how to write a message store provider, it's great. I'm not aware of any other sample message store out there. So it does not suprise me that a number of people choose to base their provider on the code in MSLMS. As such, they tend to inherit the same bugs and design flaws present in the sample.
I recently spent a couple days hacking on the MSLMS sample so that it could load under Outlook 2003. Here's a short list of the problems I found and what I had to do to fix them:
Those are just the problems I fixed. Here are some I didn't:
Anyone who has based their message store provider on MSLMS (even if it was “What would MSLMS do?“ and not just borrowing the code) needs to review their code and ensure they've addressed all of the above bugs before they approve their provider for support under Outlook 2003.
A while back, I posted an article about the fixes Jason and I had to make to the MSLMS sample message
The first answer I give to customers asking for tips on making their store provider work with the latest