Your message couldn't be delivered

The message you sent to yw32@sussex.ac.uk couldn't be delivered due to: Recipient email address is possibly incorrect.

 
Further information

5.4.1 Recipient address rejected: Access denied. AS(201806281) [DBAEUR03FT011.eop-EUR03.prod.protection.outlook.com]

If you sent this message to multiple addresses, you'll receive a notification like this for every one that didn't arrive.