in reply to How do I add an href to email?
In you mail header.Content-type: text/html
2. If you want to be more compatible, you might compose an email with different attachments using MIME::Lite - it is (IMHO) the easiest to use module for creating complex messages.
3. You could also make a CGI script that sits on a short url, gets an id and refers to the longer url, eliminating the need for HTML :-)