The message hasn't been delivered because it's stuck in a forwarding loop. Please review these details: Recipient: {Recipient} ...

The message hasn't been delivered because it's stuck in a forwarding loop. Please review these details:

Recipient: {Recipient}
Repeating address: {MailLoop}

Have the recipient use the following steps to stop forwarding their mail to the repeating address.
  1. In the Outlook on the web Options page, go to the Forwarding section, which is under Accounts.
  2. Choose Stop forwarding.
  3. Choose Save.

If you don't see Forwarding under Accounts, your mail is probably being forwarded due to an inbox rule. For more information on changing inbox rules, see Inbox rules in Outlook.