With the update I now have to get messages for all identities I created. There are times when I don't want to do this, namely I will no longer be able to read emails on my iPhone when they are downloaded to Thunderbird. I like the old format of TBird. It was clean and easy to read. Change is not always better. Ask Microsoft.

The get message button is too small. The new message button is too big and why does it clash with the other icons?

Either make both buttons the same size or better yet provide alternate buttons in the customize menu to swap out.