Personal feelings of course - not tested. I have a contact form on my site... but I use mailto links all the time as a reader - I have a protocol handler set up to use gmail by default and I think this will become more common.

I say yes, but maybe employ some tasteful iconography (stick an email icon right before or after the link, such as 'icon-envelope' from here: http://twitter.github.com/bootstrap/base-css.html#icons - maybe use CSS :before or :after classes.)