We just recently implemented exchange 2013 into our network and created a new domain. We are having an issue sending emails to various users that are in the system and have email accounts. When we try to send out an email we get a delivery error with the following message:
#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##
This user firstname.lastname@example.org has a valid email address internally and externally. We only get the error when sending to recipients within the domain but if we send from outside of the network from and external address we don't get an error and they get the emails. Please help or advice on what to look for.