Thunderbird: professional email that stays under your control
A mature open source mail client, maintained by the Mozilla Foundation, compatible with any IMAP/SMTP server — including your own. What matters for a business isn't the client, it's where the mailbox actually lives.
Thunderbird is over twenty years old, has had a dedicated foundation since 2020 (MZLA Technologies), and sees active development — this isn't an abandoned project revived out of ideology.
What actually matters: the server, not the client
Using Thunderbird on a Gmail or Outlook account changes nothing about your data sovereignty: it still lives with the mail server's operator. The real gain comes from the client + IMAP/SMTP server pair you actually control — which is what we set up as part of Trustcollab.
What it enables
Native OpenPGP encryption for sensitive exchanges, filters and rules that run client-side instead of depending on a proprietary sorting algorithm, calendar and contacts synced via open protocols (CalDAV, CardDAV) rather than a closed API.
Migration in practice
The switch happens mailbox by mailbox, with no service interruption: existing emails are imported, new ones land directly on the target infrastructure. It's a project we quote as part of a Trustcollab audit, not a checkbox.
A question about your situation?
Request a free audit, we'll look at your specific case.