What is "Deleted Messages" folder and why does keep reappearing?

[badlydrawnboy]

I have configured Mail.app to move deleted messages to the Trash mailbox and to store deleted messages on the server.

Under the .Mac tab in the mailboxes list on the left-hand side of Mail.app, I see a folder called "Deleted Messages". There's nothing in it. But I've tried deleting this folder, and it continues to reappear.

All of my deleted messages are in the Trash mailbox, so I'm not sure what this one is for.

 

[southerndoc]

Under the mailbox menu, go to "use this mailbox for" and select Trash.

 

[badlydrawnboy]

Under the mailbox menu, go to "use this mailbox for" and select Trash.

That will tell Mail.app to use the "Deleted Messages" folder on the server as Trash, so that when I delete a message in Mail.app it will go into the same folder as messages I delete from the iPhone and from .Mac webmail?

Here's the weird thing, though. I just deleted several messages from my iPhone. In Mail.app, when I click on "Deleted Messages", there's nothing in that folder. Shouldn't I see the messages I deleted from the iPhone in there?
I do have my .Mac account configured on the iPhone to use the "Deleted Messages (.Mac)" folder as Trash.