Mozilla announced on Monday (May 7th) they are looking for freelance help with their wishlist of features they would like to the Thunderbird roadmap.
The idea is really simple: there are plenty of features we would love to add to the Thunderbird roadmap but we badly lack the resources to complete them. So we decided to put them in an open repository, up for anyone to grab one and get it developed. In doing so, you will be working closely with the core Thunderbird team members who will support and guide you all along the way.
For more information and a list of projects ‘Up For Grabs’ see the Mozilla Wiki.
Source: The Thunderbird Blog