Charles McNulty wrote:
It's a Thunderbird bug/feature that's going to look like a Roundcube bug to a lot of people. If you feel inclined vote for it as a bug and leave a comment that it exhibits itself as buggy behavior in webmail clients.
This is not a bug, what Thunderbird is doing is the only right ting to do! Let me explain: IMAP doesn't have a move command, so that when you "move" a message in an IMAP client, the client has to tell the server to; 1) copy the message to the target mailbox, and; 2) mark the message as deleted. Now to have the message permanently deleted, the client would have to expunge the mailbox the message was "moved" out of. The problem is that doing so will permanently remove *all* messages (in this mailbox) marked as deleted[1]. Doing this on a mailbox accessed (maybe simultaneously) by multiple clients, and for shared folders maybe even multiple users, clearly violates the principal-of-least-astonishment.
Bob
[1]: Unless the server supports the UIDPLUS extension, see RFC 2359.