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Error message Microsoft Mailserver (OAuth2)

If you are using a Microsoft 365 or Exchange Online mailbox and receiving an error message when retrieving email, your Carerix environment may need OAuth2 authentication enabled.

How to fix this

Step 1: Check if OAuth2 is enabled

  1. Log in to your Carerix application as an administrator

  2. Go to Maintenance → Settings

  3. Check whether IMAP OAuth2 is activated in your system settings

Step 2: Request OAuth2 activation (if not enabled)

If OAuth2 is not activated:

  1. Send a message to support@carerix.com

  2. Request that IMAP OAuth2 be activated for your environment

  3. Our support team will enable it for you

Step 3: Configure your mailbox

Once OAuth2 is enabled, follow the Office 365 / Exchange Online email sync setup guide to connect and configure your mailbox for secure email synchronization.

Why does this error occur?

Microsoft now requires OAuth2 authentication (a secure two-step verification method) for all email connections to Microsoft 365 and Exchange Online mailboxes. This replaced the older username-and-password method for better security.

Important: If your Carerix environment does not yet support OAuth2, or if it is not enabled for your mailbox, email retrieval will fail with an authentication error.

Common error messages

You may see one of these errors when OAuth2 is not enabled:

  • "Authentication failed"

  • "Invalid credentials"

  • "The username or password is incorrect"

  • "OAuth2 authentication required"

  • "Unable to authenticate with the mailserver"

Note: These errors indicate that OAuth2 authentication is required, not that your password is wrong.

Additional troubleshooting

OAuth2 is enabled but email retrieval still fails

If OAuth2 is already activated but you still see errors:

  1. Follow the Office 365 / Exchange Online setup guide to reconfigure your mailbox

  2. Ensure you grant all required permissions when prompted by Microsoft

  3. Verify that your mailbox is active and accessible in Microsoft 365

  4. Check that your Microsoft account has admin access to enable OAuth2 (if required by your organization)

Error continues to appear

If the issue persists after following the steps above:

  1. Stop the email synchronization and start again

  2. Use a private/incognito browser window to prevent cached login issues

  3. Ensure you are logging in with the correct Microsoft account that owns the mailbox

  4. Contact support@carerix.com if the error continues

💡 Tip! If the error message mentions "IMAP" or "OAuth2 not configured", this confirms that OAuth2 activation is needed. Contact support with this error text to speed up the process.

If the problem is not resolved, or if you would prefer to contact our support team, please reach out to our helpdesk at helpdesk@carerix.com

Keywords: OAuth2, Microsoft 365, Exchange Online, authentication error, email sync

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