To remove a mail message
1 Set the Delete fetched setting to Yes in the Mail settings. All fetched
messages are removed from the Remote mailbox. Or,
2 Select the message(s) you want to remove with the selection frame, and
press Delete. If you want to cancel the removing, press Undelete.
The messages will be removed when you exit the Remote mailbox. However,
all fetched messages will be retained in the Received mail folder.