Sure, if they're Microsoft-branded.
fake edit: Man, I remember the good ol' days, when there was a warning going around not to open a certain email (I think it was with the title "Good Times"), because viewing the message would give your computer a virus!!!!! It was a total hoax, because it was expressly impossible for an email program to get infected just by viewing a message.
A year or two later, this one company made an email program which expressly did that. This program went on to dominate email until web mail really took off. It was a mind-gibberingly stupid thing to do, in both hindsight and foresight. I won't share the name of this company here, because I don't want to embarrass them. I'm sure they're much more responsible with security nowadays.