Enabling or Disabling SMTP Authentication for Specific Mailboxes in Exchange Online
This procedure details the steps to enable or disable SMTP authentication for individual mailboxes within the Exchange Online environment. It adheres to the guidelines provided by Microsoft in their documentation, "Enable or disable SMTP AUTH in Exchange Online | Microsoft Learn."
Note: Enabling SMTP authentication is not mandatory. It is a configuration option to control which mailboxes can send emails through SMTP servers that require authentication.
Enabling SMTP Authentication for Specific Mailboxes:
- Access the Microsoft 365 Admin Center: Log in to the Microsoft 365 admin center using administrative credentials.
- Navigate to Users: In the left navigation menu, select Users > Active users.
- Select the Mailbox: Identify the mailbox for which SMTP authentication needs to be enabled or disabled. Click on the mailbox name to open its details pane.
- Access Mail Settings: In the mailbox details flyout that appears, select Mail.
- Manage Email Apps: Within the "Mail" section, locate the "Email apps" subsection and click on Manage email apps.
- Verify Authenticated SMTP Setting: Review the status of the "Authenticated SMTP" setting:
- Unchecked: Indicates that SMTP authentication is disabled for the selected mailbox.
- Checked: Indicates that SMTP authentication is enabled for the selected mailbox.
- Save Changes: After adjusting the "Authenticated SMTP" setting as needed, click on Save changes to apply the configuration.
Additional Considerations:
- Microsoft 365 Admin Center: The steps outlined above utilize the Microsoft 365 admin center. Alternatively, SMTP authentication settings can be configured using Exchange Online PowerShell.
- SMTP Authentication Requirements: Ensure that the email account meets the requirements for SMTP authentication as specified by Microsoft. These requirements might vary depending on the SMTP server configuration.
- Security Best Practices: Enable SMTP authentication only for necessary mailboxes. Limiting the number of accounts with SMTP authentication capabilities enhances security by reducing the potential for unauthorized email sending.
By following these steps, administrators can successfully enable or disable SMTP authentication for individual mailboxes within their Exchange Online environment, ensuring alignment with their organization's security and email sending policies.