Generally, no. Unless your word processor (I don’t know MS Outlook) has a HTML mode, it will just print the tags as plain text. You could attach an HTML document to your e-mail, and it could be displayed by a browser or an HTML-savvy word processor, but you can’t (usually) just throw HTML tags into normal text and get the results you want.
There are e-mail systems (AOL, for example) that support fancy text and graphics, etc., but they tend to be system-specific, and don’t generally display the HTML either.
But – things change rapidly in the software world, mostly because it’s something somebody wants. Maybe it won’t be long until you can do what you were asking about.
“After all, she was not very much older…and a plump widowhood has its appeal.”
Dorothy L. Sayers
Murder Must Advertise