ENTRA.UF.1003.T01.Email - All Users should have a Capital-Initial Email Format
All Users should have a Capital-Initial Email Format
Description
All user emails must have the first character of the given name in uppercase and the first character of the last name in uppercase, with the remaining letters in lowercase.
How to fix
Confirm with HR the correct email format for the user.
Then run:
Update-MgUser -UserID testuser@contoso.com -Mail "JSmith@contoso.com"