* **neversenders**: a simple list of local parts (of the virtual domain) that
should never appear as senders of mails.
* **whitelist**: a colon separated list starting with "localpart:" of hosts
* **neversenders**: a simple list of local parts (of the virtual domain) that
should never appear as senders of mails.
* **whitelist**: a colon separated list starting with "localpart:" of hosts