Outlook Plug-In for custom CRM

I was part of the team that created the original Outlook Plug-In for Frankley Covey time management tools. It was quite an adventure!

The first thing I would do is make your client pick a version of Outlook, and stick with it. DO NOT let the client add support for additional Outlook versions, unless they are willing to pay for it, and willing to have the delivery time pushed back to a reasonable date.

The team I was with swore by the Slipstick website. There are several solutions to the Outlook security prompts in there.

If you can, talk to Microsoft and see if they can get you the object model for the specific version of Outlook you will be working with. We had this model printed on a large scale color printer and put it on a large wall. IIRC, it was something like 7'x5' object map. This helped tons.

You might end up creating specific classifications/namespaces for your Outlook code. It's been a while, but I remember something about a dot notation like .Email, .Task, and several others. I had to create a couple new dot namespaces for the Outlook Task object.

As razorfish noted, look up the new Visual Studio For Office Tools. This has made some stuff a lot easier.

Talk to your client and find out if they will need to connect to Exchange servers. There were two distinct ways of building Plug-ins. One mode only worked with Outlook itself, while the other talked with Exchange. This is very important to your development efforts. The models are VERY different and will cost you extra time if you pick the wrong one.

EDIT: There are a couple books that were helpful with this. The books are for Outlook 2000, so you might want to see if there are updated versions.

Building Applications with Microsoft Outlook 2000 Technical Reference

Building Applications using Outlook 2000, CDO, Exchange, and Visual Basic

Both have a lot of information on how to do deep integrations with Outlook.

You should take a look at the Visual Studio for Office Tools. You can easily create add-ins for Outlook, Word, Excel ... pretty much the entire Microsoft Office family of products.

You can also take a look at Add-In Express, but I didn't have much luck with their controls, and the VSTO for 2008 is extremely easy to use.