It is certainly one of the few “stand alone” email clients truly used and appreciated by users Mozilla Thunderbird. The email program went through a rather tumultuous period, even risking the complete closure of the project. In November 2023, we detailed the changes made to the application which, with the launch of Thunderbird 115 Supernovahave made it possible to make the software sustainable and “future-proof”.
Although it is actively used in many professional environments as a solution replacement cloud-based (what once were webmails…), Thunderbird had never shaken off the reputation of being a product more oriented towards private users. Here, the project managers are now starting to invest convincingly in communication, explaining how Thunderbird will evolve over the next few months. There is also a timetable (roadmap) quite precise which allows users to look with confidence to the future of client email aperto.
Perhaps one of the most important and long-awaited new features: support for Microsoft Exchange Server
The Thunderbird development team has been working hard on the product over the last year, introducing new features and interface improvements.
We were talking about uses in the professional field: Well, the addition of support for Microsoft Exchange is on the horizon. As it is known, Microsoft Exchange Server is a mail and calendar server widely used to synchronize information from business or organizational accounts, such as work email accounts.
Exchange has always worked with applications Outlook, as well as with some third-party software such as Apple Mail/Calendar. Thunderbird, however, has never offered full support for Exchange, unless it uses – in some cases, when intended – the standard IMAP protocol.
Support for Exchange Server will be there, but it will be partial
Those responsible for the Thunderbird project have confirmed that the developers are working to extend support to Exchange Server.
However, there is a fundamental problem. And not insignificant either. Mozilla plans to implement support for Exchange via Exchange Web Services (EWS, for short). It is a set of API (Application Programming Interfaces) developed by Microsoft to allow applications and services to communicate and interact with Exchange servers.
In September 2023, however, we confirmed that Microsoft will withdraw support for Exchange Web Services starting October 1, 2026. From that date, all requests from non-Microsoft applications will be automatically blocked. Thus, Thunderbird would also be “knocked out”.
Therefore, once October 1, 2026 is reached, Thunderbird will remain compatible only with Exchange Server installations hosted by system administrators on their own servers (self-hosted). Ultimately, it’s a setup that’s becoming less and less popular these days. In fact, it is estimated that 84% of Exchange Server implementations in 2023 were based on Microsoft cloud services.
The handshake between Thunderbird and Exchange Server may be time-limited
Despite Microsoft’s plans, the Thunderbird team has specified that native Exchange Server support via the EWS API is planned and should be implemented in the mail client in a rather short timeframe. Management of authentication, email, calendars and contacts will also be supported within Thunderbird.
Sean Burke, software engineer at Mozilla, said that EWS is currently the best way to enable support for both Exchange Online and for server software installations on user systems.
The use ofAPI Graph, so advocated by Microsoft as a replacement for EWS, has been taken into consideration and will probably be evaluated in the future. As it stands, however, Burke points out that it provides more limited features when compared to EWS and lacks some functionality for desktop applications.
In short, between the lines we read that the Thunderbird developers are not convinced that Microsoft is respecting the roadmap. Because if the EWS really “closes the taps” on October 1, 2026, the Graph API cannot provide reduced functionality compared to the interface that is set aside.