A while back we reported that certain branches of the French government were switching their desktop email clients to Thunderbird.
One of these branches who switched to Thunderbird was the French military. However, in order for Thunderbird to fit their particular requirements, quite a few modifications were required.
Thanks to the openness of Thunderbird, the French military were able to develop extensions to address some of their needs and modified the source code to address core changes. But they didn’t stop there. Instead of just keeping their changes to themselves, they open sourced them. Then, together with Mozilla they bundled the add-ons with a Thunderbird and created their own fork, named Trustedbird. Kudos to the French military!
Mozilla 
Just a few days after releasing Thunderbird 3 RC1 (that we 
The casual observer may simply write off Postbox as being another in a long line of hopeful desktop email client replacements, but there’s more to this powerful email client than meets the eye. A familiar layout, a bevy of smartly integrated features, reliable performance, plug-in support make Postbox a dream-come-true for anyone who relies heavily on their inbox to keep their business and personal lives organized.
01.net today reported (