You could also use Outlook Redemption, which is supported from managed code; I'm not immediately sure if it has a simple MAPISendDocuments replacement, but Dmitry's helpful if you have questions.
As for "crashes and burns", here's another quote from an MS support guy, here
It's the sort of thing that'll mostly work. It'll work while you're writing it. Then it'll work while you're testing it. It'll work while your customer is evaluating it. Then as soon as the customer deploys it - BAM! That's when it'll decide to start having problems. And Microsoft ain't gonna help you with it, since we told you not to do it in the first place. :)
