When I try to "Sign in with Microsoft" I am getting a "Cannot Authenticate" error message

Issue symptoms

I try to integrate my Office 365 email account with my Sell account. I follow the steps to integrate my email and when I select Sign in with Microsoft I receive the error message Authentication: Cannot Authenticate.

Resolution steps

The error message Authentication: Cannot Authenticate indicates that the authorization of the OAuth application on the Office 365 side was successful. However, when the system tried to use the provided credentials to sign in to the server to verify that the integration is successful, it encountered an SMTP AUTH error. To resolve this issue:

Ensure the User name and Primary email address fields match in the Microsoft admin settings. If there is a mismatch, Microsoft won't allow for the email to integrate with Sell. If these fields match, continue to the next step.

The Office 365 email admin needs to turn on SMTP AUTH on your Office 365 email account.
For more information, see Use the Microsoft 365 admin center to enable or disable SMTP AUTH on specific mailboxes.

After you turn on the email protocol, follow the steps to integrate your Office 365 email

Important: If you turn on SMTP alone, it won't resolve this error message. This email protocol is often turned off in Office 365 by default and an email admin needs to turn on both IMAP and SMTP and SMTP AUTH for the mailbox, as these protocols are what Sell uses to synchronize and send emails in your account.

For more information, see Troubleshooting email integration errors.