.local Address Not Found (Exchange)


Exchange+ users that have been recently migrated may encounter the following error when sending mail:


Delivery has failed to these recipients or groups:

'John Doe'
The email address you entered couldn't be found. Please check the recipient's email address and try to resend the message. If the problem continues, please contact your helpdesk.

Diagnostic information for administrators:

Generating server: MBX000.mailprotector.local

Remote Server returned '550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found'


This error indicates an issue with a cached address route, and can be resolved in one of two ways:

Method 1 - Removing a single auto--complete entry:

  • In Outlook, compose a new message
  • Begin typing the recipient address
  • At the auto-complete prompt, click the "X"
  • Delete the contents of the "TO:" field, and manually key in the entire address


Method 2 - Removing all auto-complete entries:

  • Navigate to File > Options > Mail
  • Scroll down to the "Send Messages" section
  • Click the "Empty Auto-Complete List" button


If you continue to see this error, please contact Mailprotector support by using the "Submit a Request" button below.

Have more questions? Submit a request