Hi MS support,
This month, we are facing some of the new users got randomly delivery has failed to these receipients or group from external and internal sender.
Diagnostic information for administrators:Generating server: email server
IMCEAEX-_o=First+20Organization_ou=Exchange+20Administrative+20Group+20+28FYDIBOHF23SPDLT+29_cn=Recipients_cn=email address
Remote Server returned '550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found'
is there a way to resolved the problem?