MailMate crowd funding campaign
Most email clients suck. If you use a Mac and you care about sending standards-compliant emails using a fast and robust native OS X-only application, then I urge you to look at MailMate. I’ve been using it for years, and it never misses a beat.
It’s a one-man-show, and the developer needs help in order to continue working on MailMate. Check out the crowd funding campaign page.