Geary is on of the nicest email apps available on Ubuntu today. We love it so much we did a little write up on it back in April. See it HERE.
The Geary email client is being developed by Yorba, the same team responsible for Shotwell, a photo manager that is now the default photo application in Ubuntu.
The latest version of Geary includes per-account full text search, automatic save to draft, a nice user interface, per-folder unread email count, support for Outlook.com, enhanced “show external images” preference, better handling of attachments, malicious link checker, and hundreds of bugs fixed and small improvements. My biggest love for Geary is its lightweight feel and speed on older computers.
My OS of choice right now is Elementary OS Luna and Geary is the pre-installed default mail client. EOS Luna is derived from Ubuntu 12.04 LTS and unfortunately the newest version of Geary 0.4 only works on the newest versions of Ubuntu, not the LTS (long term support) version. This is however an opportunity and a challenge for anyone with some skill to backport Geary 0.4 to Ubuntu 12.04 LTS. If you can successfully do so, you'll win the bounty which has jumped to $600 (pushed up with our little bounty donation).
You can learn more about the bounty here and if you have the skills to tackle this or know someone who does, please spread the word! If you dont have the skills consider making a donation to the bounty to help it out. Thanks!