We have made a curious observation. I would like to describe it in the following.
Mail addresses were set up in a domain under Plesk. Some of them have forwarding addresses to other local mail addresses.
If one of these local addresses is deleted from Plesk, it will also disappear from the list of forwarding addresses. This is fine. But internally the address seems to still exist, because if you write to the main address, you get the error message "Sorry, the mail address does not exist". So it still tries to deliver mail to an address that is no longer in the forwarding list. It is as if it is still invisible in the forwarding list. But since it no longer exists as a real mail address in Plesk, this error message appears.
Is this a bug?
Mail addresses were set up in a domain under Plesk. Some of them have forwarding addresses to other local mail addresses.
If one of these local addresses is deleted from Plesk, it will also disappear from the list of forwarding addresses. This is fine. But internally the address seems to still exist, because if you write to the main address, you get the error message "Sorry, the mail address does not exist". So it still tries to deliver mail to an address that is no longer in the forwarding list. It is as if it is still invisible in the forwarding list. But since it no longer exists as a real mail address in Plesk, this error message appears.
Is this a bug?