Claws Mail 3.10 was released today with important new features such as auto-configuration of account email servers based on SRV records, so for instance if you enter a Gmail account, Claws Mail will automatically determine the connection details (ports, server names, security protocols, etc.).

The new release also includes proper certificate verification, an option to avoid saving drafts for emails that are to be sent encrypted, a new Libravatar plugin which displays user avatars from libravatar.org and more.

Thunderbird 5.0 has been released today, bringing a new addons manager (Firefox-style), NotifyOSD notifications, tabs can be reordered and dragged to different windows, the account creation wizard has been improved and many other improvements and bug fixes. See the release changelog here.

The Thunderbird Next PPA provides Thunderbird releases from the beta channel so each time a new beta version is released, it will be available to install via this PPA, but of course with a delay because it takes a while for new versions to be packaged and tested.

Even though in the beginning of the default email client session at the Ubuntu Developer Summit in Budapest, it looked like it's certain that Evolution will stay as default in Ubuntu 11.10, towards the end of the session things changed and it was decided to stay with Evolution for now BUT switch to Thunderbird as the default email client in Ubuntu 11.10 Oneiric Ocelot as long as it integrates with the desktop.

The Thunderbird desktop integration is not just about Unity (Launcher badge or quicklists) but also E-D-S, contacts as well as better integration with the GTK theme. And of course, there's also the CD space issue.

To see when / if Thunderbird becomes default in Ubuntu 11.10, keep an eye on the default email client blueprint - when all the "work" items are marked as done, Thunderbird should be added as default (the blueprint needs to be updated firstly with todays notes, etc.).

You can read the session notes here.

You could easily install Thunderbird 3.1.x in Ubuntu using Ubuntuzilla, but that was only available for 32bit users.

A PPA repository is now available which provides the latest Thunderbird 3.1.6 (final, not daily builds) for Ubuntu Lucid - both 32bit and 64bit.

To add the PPA and install Thunderbird 3.1.6 in Ubuntu, simply paste the following commands in a terminal:

sudo add-apt-repository ppa:ricotz/ppa && sudo apt-get update
sudo apt-get install thunderbird

Update: I've replaced the original PPA in this post with a new PPA which provides Thunderbird 3.1.6 packages for Ubuntu Maverick (10.10), Lucid (10.04), Karmic (9.10), Jaunty (9.04) and Hardy (8.04)!

If you found the Ubuntuzilla way of installing Thunderbird 3.1 in Ubuntu a bit too hard, here is a .deb file you can download and install Thunderbird 3.1 in Ubuntu.

Note: this is the unmodified Mozilla release binary of Thunderbird, packaged into a .deb by the Ubuntuzilla project. This means they were only able to package it for 32bit since Mozilla does not provide 64bit binaries.