Mail Forwarding in Horde

[Peter Strydom]

Hi, I have set up a number of email accounts in CPanel and all seems to be working well. I have three emails addresses which I have forwarded to other email accounts. When I look at the mailboxes in Horde one of the original email accounts is empty telling me that the forwarding setting are working, but on the remaining 2 accounts the original email accounts still has copies of the forwarded mail even after successfully forwarding, resulting in me having to manually delete these mails once a month.

Question is why is one account working fine yet the remaining 2 are not deleting the mails once it has forwarded them to the new address?
(progressit.co.za)