Plesk based email bouncing with following error message:
<firstname.lastname@example.org>: Sorry. Although I’m listed as a best-preference MX or A for that host, it isn’t in my control/locals file, so I don’t treat it as a local file. (#5.4.6)
First check that the domain really does exist in Plesk and the MX records point to it.
Ensure that the domain is not disabled in Plesk
If the problem presists, check that the domains are added to the following files:
(This is automatically done when added to Plesk).
The problem is likely caused by one of the above files becoming corrupt or missing the correct domain entries for some reason. If so, simply rebuild the Qmail configuration files by running: