First I have set up a "Pop/IMAP mail server" on "Incoming Mail" page and it says "The connection was successful." if click "Test Connection" button.
Then I set up a "Mail Handler", however, it shows message "No messages in mailbox" when I click "Test" button, the detail information is: "No messages were found in this mailbox. To properly test this handler, populate your mailbox with a few emails first and re-run the test. Found 0 unprocessed message(s) in the imaps folder."
Actually, there is email on incoming box.
Is there anything wrong?