Forum Discussion
Email address assigned to group bounces back
Odd problem that isn't getting resolved by MS Support despite much effort on my part. I created a new group (call it MyGroup) and then assigned it the email address info@mycompany.com. When I send ...
We had something similar happen, but it wasn't an Exchange problem.
If you're sending using the full Outlook client to run your tests, make sure you're not using a "cached" email address from the AutoComplete list, especially if this email address used to be an alias and is now going to be a full DL.
https://support.microsoft.com/en-ca/help/2199226
We had this happen when we moved DLs from being hosted on-prem to hosted in the cloud. There is a unique ID that changes in the background, even though the email address is the same. The error message is a similar "address not found" error, which was VERY frustrating to track down.