Undeliverable Emails Received When an Email-to-Case Routing Address Has Been Deleted

## Expected Behavior When a Routing Address Is Deleted
When the routing address is deleted and an inbound email is forwarded to the Salesforce Email Services Address, one of two Mailer-Daemon Non-Delivery Report (NDR) responses occurs, depending on how the local email system forwards or redirects email from the internal routing address to the Salesforce Email Services Address:

1. The Routing Address inbox receives a Mailer-Daemon NDR response.
2. The original sender of the email receives a Mailer-Daemon NDR response.

This is expected behavior. Once the Email-to-Case Routing Address is deleted, the associated Salesforce Email Services Address is no longer valid and cannot accept inbound messages.
## Sample Error Message
When the delivery fails, the NDR message typically reads: "551 [EmailServicesAddress] is not a valid address."
This confirms that the Salesforce Email Services Address is invalid because the routing address record no longer exists in the org.
## Resolution Steps
To restore email delivery, recreate the Email-to-Case Routing Address in Setup. Once recreated, a new valid Salesforce Email Services Address is generated. Update your email forwarding rules to point to the new address.

See Also:
Recreating error free inbound routing addresses
Learn why email to case service addresses are blank in refreshed sandboxes