Philipp Kewisch, writing for Mozilla:In a conversation with Slashdot, a spokesperson of Mozilla acknowledged that the general sentiment is "Thunderbird code needs to be modernized and the dependencies on the Mozilla code framework need to be reduced. This may include re-implementing or migrating features to make better use of web technologies."(Footnote: Back in 2012, Mozilla announced that it would reallocate most of the paid project members to other projects, handing off the responsibility for the project to the volunteer community that had formed around Thunderbird. This group met in Toronto in 2014 to discuss the future of Thunderbird and formed the Thunderbird Council, a group of individuals that has the power to make business decisions going forward.)