I think you are running in the infamous T3459 "As long as the decrypted content of a crypto mail is loaded a mail can't be moved" You have to unselect the mail and then move it without opening it. E.g. by right clicking it. I know this is horrible and it's a major problem but I don't see how we can fix it in our architecture. As we replace the mail content with the decrypted stuff we have to prevent "Write" Events by Outlook. For Move if you block a write event, the move fails. But we don't have any idea in our addon when a write comes from a move. I spent a lot of time on this and have not yet found a good solution. But I think the workaround is kinda ok.

And yes I would love to show a warning / info about this. But I do not know when a move takes place. Outlook sends out write events several times if you "modify" a mail (by replacing the content with the decrypted content).

> If trying to open the (write) "new mail" window afterwards, Outlook crashed.
I'll try to reproduce this.