... without getting one of those "An application is doing something evil with your email, would you like to be complicit (Y/N)?" dialog boxes (boxen?).
See Important Security Notes for Microsoft Outlook COM Add-In Developers.
I've played with a little Outlook Addin development before, this looks like one of the more useful articles around on the security model - which for some reason is quite difficult to get a useful Google result about.
I was surprised that a Body was considered sensitive, but thinking about it, harvesting detail is probably as harmful as mass emailing. If not more.
It doesn't really help with the BlogWave Calendar adapter (where I hit the scenario), but considering it's really designed to be used interactively (eg, with a logged on user), it's probably not a terrible tradeoff.