This should be good news for users with privacy concerns, but it has its drawbacks. Thunderbird recently teamed up with MailFence, an end-to-end encryption service based on OpenPGP.

Those looking to create a new account using the client might have an unpleasant surprise. On the contrary, the same somewhat outdated UI is still in use, forcing newcomers to look for more intuitive alternatives. New users might not feel the same way, as Thunderbird is not known for its revolutionary looks. If you are a long-time user, the application's UI won't be a problem. All those features are found within Portable Thunderbird as well - a version dedicated to users who change devices or locations often, sparing the effort of setting up the client again and again. Features like email, news feeds, newsgroups, calendars, and PIM chat forms the core of this software, including tons of functionality added by countless extensions.

Mozilla Thunderbird is a popular e-mail client adopted by individuals and organizations all over the world.

Mozilla thunderbird portable