Exchange decommission · SMTP dependencies
Is SMTP relay the last reason Exchange is still running?
Uninstalling the last on-premises Exchange server removes its Receive Connectors. Printers, scanners, monitoring systems and business applications that use those connectors can lose mail relay. Move the dependencies first.
Microsoft source · Last technically verified · Original documentation ↗
Before uninstall
Check what still depends on Exchange.
Replacing the SMTP relay does not prove Exchange is otherwise removable.
Receive Connectors still serving devices
Inventory anonymous relay connectors, source IPs and applications. This is the part SMTPReady might replace.
Centralized Mail Transport or hybrid routing
If outbound mail still traverses Exchange on-premises, resolve that flow under Microsoft’s decommissioning guidance.
Exchange attribute authority and recipient management
Verify the required source-of-authority and management path before uninstalling.
Microsoft’s initial connector discovery command:
Get-ReceiveConnector | Where-Object { $_.PermissionGroups -match 'AnonymousUsers' } |
Format-Table Name, Bindings, RemoteIPRanges -AutoSizeTwo different decisions
Moving SMTP relay is only part of Exchange retirement.
Move dependent SMTP senders
Use Microsoft 365 connector relay where possible. If a private Windows bridge using one relay mailbox fits, SMTPReady may cover the exception. If routing is broader, use a full SMTP server or hosted service.
Compare alternatives →Finish Microsoft’s prerequisites
Verify hybrid configuration, centralized transport, directory/attribute source of authority and other dependencies under the official decommission procedure.
Open the Microsoft checklist ↗