Once you connect your domain to Microsoft Workspace, you need to create a new user, assign a license and enable SMTP for this email account.
To do so follow these steps:
Go to your Microsoft admin page (login with the admin account).
Click on the Active Users tab under Users
Click on Add a user
Fill out the details (name, display name, and email address), and make sure to choose the correct domain in the domain section:
Buy a license for this new user (if you don't have any available):
Click Next on the two following steps and Finish adding.
You have created a new user account now.
The next step is to enable SMTP for this account. Click on the account that you just created, and a side window will appear.
Microsoft will need a few minutes to prepare mail settings for a newly created account, so please wait a few minutes and reload the page.
Go to the Mail tab, and click on Manage email apps:
Make sure IMAP is enabled and click the checkbox to enable SMTP.
Click on Save Changes.
Wait one hour for changes to take effect, and add this account to Instantly by using Microsoft connector:
To learn more about connecting Microsoft accounts to Instantly, check this article: