With this neat little extension, users of web-based e-mail can click on mailto links and have them open their e-mail Compose page, instead of MS Outlook. It eliminates the time-consuming hassle of copying the e-mail address, opening your e-mail Compose page and pasting it in. Instead, one click and you're ready to start typing. Alternate e-mail sites can be enabled in the right-click context menu. It's a slick solution to a major annoyance, I love it.
WebmailCompose