[curtiss]

Unfortunately, Leppy, you're most likely not going to find a global fix, other than to stop using mailto links and start implementing contact forms instead.

There is no way, through a Web site, to dynamically change the security level within IE (thank God for that, otherwise the security levels would be completely and totally useless).

You have to look at this in a similar fashion to the way we all used to account for the fact that some users would have frames and/or javascript disabled. You just have to put a warning somewhere that lets people know they might experience the issue, and how to fix it if they choose to do so.