We have an Exchange 2013 on premise installation with 3 mailbox servers in a single dag and two cas servers configured as SMTP relay proxy servers. I have a receive connector for internal relay set up. TLS is selected for authentication and anonymous for permissions group. Scope is set to vLANs where servers reside.
I have created a contact object in AD for the SMTP address.
My problem is the translation of sender SMTP address to display name when relaying internally. This works inconsistently. When using telnet from one server (2008 R2) the display name shows correctly in outlook. When using postfix from a RHEL 6 server, outlook only shows the SMTP address and not the display name