need to remove an .onmicrosoft.com alias from a DL created in an AD so that it can be added to a DL created in the Exchange

Question

This is the view of my screen in the active teams and groups in Microsoft 365 admin. In the Aliases column it has the email address that was created in the active directory. I have manually changed the name of everything for that old email in the active directory to a "remove" email. I am eventually going to remove that old Distribution List, but for the time just want to make sure that the one created in the Microsoft 365 admin center is working first. When I click on the old DL in the admin center the name of the email has been changed successfully everywhere except in the .onmicrosoft.com alias. I need to remove this so that I can assign that old DL email to the new DL email. Can anyone help me with this problem. I have considered removing the old DL from the Active Directory and then just creating a new alias with the .onmicrosoft.com for the newly created DL in the admin center, but hesitant so as not to mess up the messaging delivery system. The new DL email that has the same name as the original is working properly, so I am just wanting to get this last piece taken care of. Thank you in advance for any help, or suggestions that someone can provide.

Answer 1

The only way to remove it would be to temporarily disable directory synchronization. You're probably just being overcautious here, the onmicrosoft.com address is rarely used, so you should be fine by just deleting the DL.