Steps to Authenticate SMTP from a Microsoft Admin account
Please check if the following setting is enabled:
Open the Microsoft 365 admin center and go to Users > Active users.
Select the user, and in the flyout that appears, click Mail.
In the Email apps section, click Manage email apps.
Verify the Authenticated SMTP setting: make sure it is checked/enabled.
5. When you're finished, click Save changes.
After done with the above changes please try to set up the SMTP setting
When multifactor authentication is enabled, also follow these steps
Click Add sign-in method
Choose the "App password" method
Enter "Clientjoy SMTP"
On next, copy the password and use this password in Clientjoy while setting up SMTP