I was adding a little style to my company's HTML email newsletter template and came to wonder whether and to what extent CSS is supported in various email clients. A google search came up with just a very small handful of discussion threads indicating that gecko and outlook definitely do support it. My own experience with outlook is that it parses it much like IE. We do have an alternate text-only email for those who can't get html at all. So, the question: is it a good idea to use CSS in email?
bonus question: same deal for Flash - I was thinking of embeding a really small flash movie in the email. This also seems to show up fine in outlook. Any caveats on this apart from the usual issues around requiring the plugin?