After adding a new domain to an existing Office 365 tenant, how do I make that tenant default in Outlook

Question

We have an existing Office 365 account that uses ******@abc.com, and we expanded the business and it is now ******@abcd.com. We had no issue setting up the new domain, and we changed the usernames within Office 365 admin center, but within Outlook we are still sending as ******@abc.com. I was able to add the ******@abcd.com email to the From line, but it is not default and has to be changed. Is my only option to remove the old account and add back using the new ******@abcd.com? Is there a way to default to the new domain ******@abcd.com within Outlook for all my users?

Answer 1

Unfortunately, Outlook requires profile reconfiguration in order to reflect such changes.

In addition, make sure you've changed both the UserPrincipalName and the PrimarySMTPAddress to match the new domain, as otherwise users might get confused which value to use.