Add a multipart alternative message (ref #40 @ tedivm/Fetch)

In tedivm/Fetch, issue #40:
> Thanks!
> 
> Maybe it's a good idea to add the email to the test suite to prevent it from breaking in the future. I have the test suite up and running now, but I'm not sure what's the easy way to add an extra message.

This adds a message like that. I've replaced actual email addresses with (valid) fake ones, I guess that's not really an issue though.