We wanted to let you know that we are aware of this issue with mail and investigating. We are also investigating an issue where attachments are going missing with a UI error. You can ind further details and help in our help article here.
I have the exact same issue on several alt accounts. Seems to be only an issue for accounts that I have not logged into recently and that may have older unread mail on them.
Please fix this ZOS. I have two accounts where I store Motifs, and one has 44 messages full of Motifs I can't read and another with 48 messages full of Motifs I can't read. That's a lot of Motifs and a lot of lost gold