Have a client how has about 16 mail. We have one mail box that can't send mail to anyone within his domain. He can send outside his domain and is receiving just fine from everyone internal and external. I filled out a service request but they can't find the issue. Any ideas?
The error code we get is:
Diagnostic code = MailRecipientUnknown; Reason code = TransferImpossible; Status code = 511
[ #5.1.1 smtp;550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found]
He is on Windows 7 with Office Professional 2010
Any ideas?