Migrating inbound, outbound, and internal relay mail flow to Exchange Server 2016 during a migration project.
Remove Internal Exchange Server Names and IP Addresses from Message Headers
How to remove the names and IP addresses of your internal Exchange servers from the headers of outbound email messages.
There's No Need to Create Connectors for Internal Exchange Server Mail Flow
Internal mail flow for an Exchange Server environment can be broken due to a number of common mis-configurations.
Event ID 9041, An exception has been thrown: Microsoft Exchange Assistants TransientMailboxException
I recently encountered a mail flow problem between two of my test lab environments that was being caused by the DNS configuration on the receiving server’s network interface.
MX Records for Exchange Hybrid Deployments
Exchange Hybrid deployments with Office 365 have several options for how the MX records for the domain can be configured.