🛡️ Overview

Security software such as antivirus programs, firewalls, or network security tools can sometimes interfere with Mailbird Next’s ability to connect to email servers. This can cause errors when sending or receiving emails, adding accounts, or syncing your inbox.

⚠️ Error References

The following errors in Mailbird Next may indicate antivirus or firewall interference:

• Error #19 — Connection blocked or interrupted by security software
• Error #11 — Connection timed out (may be caused by firewall rules)
• Error #17 — Connection refused (may be caused by firewall or port blocking)

🔍 Common Symptoms

• Mailbird Next cannot connect to your email server.
• Emails fail to send or receive intermittently.
• Account setup fails with connection or timeout errors.
• Mailbird works on other networks but not on your current one.

🛠️ How to Fix It

1. Temporarily Disable Your Antivirus or Firewall

Try temporarily disabling your security software to see if it resolves the issue:

• If the issue goes away, your security software is the cause.
• Re-enable it afterwards and follow the whitelisting steps below.

2. Whitelist Mailbird Next

Add Mailbird Next to your security software’s allowed applications list (sometimes called an exclusion or exception list).

1. Open your antivirus or firewall settings.
2. Look for an Exceptions, Exclusions, or Allowed Apps section.
3. Add Mailbird (or its application path) to the list.
4. Save and restart Mailbird Next.

3. Check macOS Firewall Settings

macOS has a built-in firewall that may also block connections:

1. Open System Settings → Network → Firewall.
2. If the firewall is enabled, click Options…
3. Ensure Mailbird Next is listed and set to Allow incoming connections.
4. If it’s not listed, click + and add it.

4. Ensure Required Ports Are Open

Mailbird Next needs access to the following ports:

Ask your network administrator to ensure these ports are not blocked.

5. Disable VPN Temporarily

If you’re using a VPN, try disconnecting it temporarily. Some VPNs interfere with email server connections.

💬 Need More Help?

If you’ve tried the steps above and are still experiencing issues, please contact our Customer Happiness Team. We’re always here to help.