What's new

Big announcement here! UniversalMailer reached version 3!

Version 3 is a complete rewrite of version 2, which is both something good and something bad. Here's a list of good things:

The plugin improved its email handling features, especially when dealing with attachments (both inline and not inline)
You don't need an HTML signature anymore, UniversalMailer will do its job even with plain text emails.
You can now provide your own CSS for email customization. This is a sort of an advanced feature but it's a major feature for those of you that needs deep style customization.
UniversalMailer source code now stands by its own: version 3 dropped the mimetic library dependency, which was really too much for it: it now includes a custom made MIME pseudo-parser suited for its specific job. This is maybe of no importance to the vast majority but worth a bullet point here :-)
There's a new preference panel! This version is an oversimplified translation of the v1 and v2 panels, it should be more user friendly!

And here's the list of bad things:

Version 2 was largely tested by users, version 3 it's not at the moment. Expect bugs (hopefully, only new bugs and not regressions).
Version 3 dropped supports for older OS X, this is something I really like but you may disagree.