This process involves accessing the Microsoft 365 admin center and adjusting a user's license settings.

Prerequisites:

• Administrator access to the Microsoft 365 admin center.

Steps:

1. Log in to the Microsoft 365 Admin Center:

   • Open your web browser and go to: https://admin.microsoft.com/

   • Enter your administrator credentials to log in.

2. Navigate to Active Users:

   • In the left-hand navigation pane, expand "Users".

   • Click on "Active Users".

3. Select the User:

   • Locate the email account for which you are experiencing SMTP errors.

   • Click on the three dots (More actions) next to the user's display name.

4. Manage Product Licenses:

   • From the drop-down menu, select "Manage product licenses".

5. Access Mail Settings:

   • In the "Product licenses" pane that opens on the right, ensure the appropriate license is selected (e.g., Microsoft 365 Business Standard, Enterprise E3, etc.).

   • Scroll down and locate the "Mail" section.

6. Adjust Authenticated SMTP Setting:

   • Under the "Mail" section, find the "Authenticated SMTP" setting.

   • If "Authenticated SMTP" is NOT already selected: Select the checkbox next to "Authenticated SMTP".

   • If "Authenticated SMTP" IS already selected: Unselect the checkbox, and then immediately re-select it. This acts as a refresh for the setting.

7. Save Changes:

   • Click the "Save changes" button at the bottom of the pane.

After completing these steps, allow a few minutes for the changes to propagate through Microsoft 365. Then, attempt your Office 365/Outlook integration again to see if the SMTP errors are resolved.