Hello,
If you are using office 365 then try outlook.office365.com in the SMTP server.
if you are using trial office 365 account xyz@abc.onmicrosoft.com then it won't work because by default MFA is disabled for the trail account.
If you are using gmail with 2 Authentication then setup a App password as shown below
Login your Gmail account,
Go to Manage Account -> Security
Select other and type a name
Enter a name and click on Generate you will get a pop up window, copy the password as shown below.
Now use this password in your BC SMTP Mail Setup.
