How to find our your Office 365 default domain name?
- Please log in to your Office 365 Admin Center using your Global Administrator credentials.
- Under Settings click on Domains (or just click here). FYI: Sometimes, Domains may be located inside Setup instead of Settings.
- Look for the domain name marked as (Default) in the Domain name column. This is your default domain name for your Office 365 tenant. It may or may not be the same as your Office 365 tenant name.
Check the screenshot below: