It's probably because Mozilla announced that Thunderbird is now in maintenance mode. They do not plan to add features or make major changes anymore. To some th

It's probably because Mozilla announced that Thunderbird is now in maintenance mode. They do not plan to add features or make major changes anymore. To some that may mean Thunderbird is complete and mature, but RedHat must believe that Thunderbird is now a dead end. https://wiki.mozilla.org/Thunderbird/New_Release_and_Governance_Model https://wiki.mozilla.org/Thunderbird/New_Release_and_Governa...