mail routing

Discussions tagged with mail routing on WindowsForum.com focus on hybrid Exchange environments and the technical plumbing that keeps on-premises Active Directory and Exchange Online in sync. A recurring theme is Microsoft's move to retire the last Exchange Server by enabling writeback for cloud-managed remote mailboxes through Entra Cloud Sync. This change directly affects mail routing in hybrid setups, where directory attributes must flow correctly to ensure messages are delivered to the right mailbox. The tag covers the infrastructure decisions and migration steps that IT administrators face when simplifying their mail routing topology, including decommissioning on-premises servers while maintaining proper message flow and directory synchronization.