This is using MS Exchange 2013 server. Recently, a user always can't receive external incoming mails from a email domain, while all other users without problem. In EAC > delivery report, this is the error message:
Delivery report for email@example.com
11/5/2015 from mailserver.def.local
This message was rejected by recipient's email system. Please check the email address.
(LRT=); (LED=554 5.1.0 Sender denied) (FQDN=);(IP=)
I ever checked the usera's junkmailconfiguration, and found that the above incoming email address wasn't listed.
Thanks in advance.