Office 365 SMTP authentication error in BillQuick

When setting up SMTP in BillQuick for your Office 365 email account, you may get the following errors:

• The SMTP Server requires a secure connection or the client was not authenticated. Error 535 5.7.139, Authentication unsuccessful, SMTPClientAuthentication is disabled for the Tenant.
• The SMTP Server requires a secure connection or the client was not authenticated. Error 535 5.7.139, Authentication unsuccessful, basic authentication is disabled.

This happens because Authenticated SMTP is not enabled for your Office 365 mailbox. To enable Authenticated SMTP for your user account, ask your Office 365 email admin to follow these steps:

1. In the Microsoft Admin Center, go to Users > Active Users.
2. Select the user for whom you want to enable this setting and, in the flyout that appears, click Mail.
3. In the Email apps section, click Manage email apps.
4. Select the option Authenticated SMTP and save the changes.

You can now set up your SMTP in BillQuick successfully. Check out the relevant documentation from Microsoft for more details.