> We plan to launch the first phase of built-in support for Exchange, as well as Mozilla Sync, in a future Nebula point release (e.g. Thunderbird 128.X). Although these features are very close to being finished, technical obstacles prevented them from being ready today. Alex will keep you updated in his monthly Thunderbird Monthly Dev Digests.<p>> For advanced users who want to help test our initial implementation of Exchange (currently limited to Mail), we’ve hidden the option behind a preference. This Wiki page explains how to enable it. While we definitely welcome your testing and feedback, please keep in mind this feature is currently experimental, and you may run into unexpected behavior or errors.<p>It ia finally coming. I really don't know what is so special about Exchange that took them all these years? There were already an extension to allow Exchange for a decade or so.