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How to prevent Windows 11 Defender from blocking Mailbird

  1. Mailbird
  2. Troubleshooting
  3. Issues Sending or Receiving Emails
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Oliver Jackson
  • June 12, 2025 09:58
  • Updated

🔧 Troubleshooting Mailbird Email Issues

If you're having trouble sending, receiving, or syncing emails in Mailbird, the issue may be caused by your Windows 11 Firewall blocking Mailbird's connection to email servers.

This article walks you through how to allow Mailbird through the Windows 11 Firewall using a simple step-by-step guide, complete with screenshots for a smoother experience.

🛡️ Allowing Mailbird Through the Windows 11 Firewall

Follow these steps to prevent your Windows 11 Firewall from blocking Mailbird:

  1. Open Windows Settings by clicking the Windows icon in the bottom-left corner of your screen, then select Settings.Step_1.png

  2. Click on Privacy & security in the left-hand menu.Step_2.png

  3. Select Windows Security from the list of options.Step_3.png

  4. Click on Firewall & network protection on the right-hand side.Step_4.png

  5. Scroll down and click Allow an app through the firewall.Step_5.png

  6. In the new window, click the Change settings button.Step_6.png

  7. Click Allow another app….Step_7.png

  8. In the next window, click the Browse… button.Step_8.png

  9. Navigate to Mailbird’s installation folder:

    • By default, it's located at: C:\Program Files\Mailbird

    • Select the Mailbird.exe file (you may only see it listed as “Mailbird” with a white envelope icon), then click Open.Step_9.png

  10. Back in the app selection window, click Add.

✅ You're All Set!

Mailbird should now appear in the list of allowed apps, and your Windows 11 Firewall should no longer interfere with its connection to email servers.

🆘 Still Having Issues?

If you're still experiencing problems with sending, receiving, or syncing emails, please revisit this article for further troubleshooting steps or contact our support team for additional help.

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