Have you checked out Exchange EWS Provider [1], currently maintained by Ericsson? This has been around for a few years [2], and when the developer could no longer spend time on it, Ericsson took it over. The extension is not perfect, but you can get some stuff done.<p>Another alternative is the DavMail gateway [3], which runs as a separate (Java) program that sits between your Exchange server and Thunderbird. [I haven&#x27;t used this one for years ever since the Exchange EWS provider became available]<p>[1]: <a href="https:&#x2F;&#x2F;github.com&#x2F;Ericsson&#x2F;exchangecalendar" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;Ericsson&#x2F;exchangecalendar</a><p>[2]: <a href="http:&#x2F;&#x2F;www.1st-setup.nl&#x2F;wordpress&#x2F;poducten&#x2F;exchange-ews-calendar-and-tasks-add-on-for-thunderbird-lightning&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.1st-setup.nl&#x2F;wordpress&#x2F;poducten&#x2F;exchange-ews-cale...</a><p>[3]: <a href="http:&#x2F;&#x2F;davmail.sourceforge.net" rel="nofollow">http:&#x2F;&#x2F;davmail.sourceforge.net</a>