Have spent a lot of time trying to find help on this but to no avail. Ended up doing the testing ourselves to see what was happening, we run Office 2000 and Notes R5, with the office install we have removed all outlook components.
When we click on send to mail recipient we get a mapisvc.inf error and put plainly it was really starting to get on our nerves as all the support sites were saying that all you have to do is install notes then office. I had installed a standard office setup and it worked though?
The answer my friends is the component under outlook called INTEGRATED FILE MANAGEMENT.
Hope this helps...