[BlueOnyx:06428] No postmaster emails fails to pass RFC's

[Darrell D. Mobley]

How do we fix this:

ERROR: One or more of your mailservers does not accept mail to
postmaster at someclientsdomain.com. Mailservers are required (RFC822 6.3,
RFC1123 5.2.7, and RFC2821 4.5.1) to accept mail to postmaster.