🥶 What This Article Covers
This article walks you through the most common steps to resolve issues where Mailbird freezes, hangs, or becomes unresponsive on Windows.
Work through the sections below in order and re-test Mailbird after each step.
🛡️ Check Your Antivirus and Firewall
Security software (e.g. Windows Defender, third-party antivirus, or firewalls) is one of the most common causes of Mailbird freezing.
- Exit Mailbird completely before changing any antivirus or firewall settings.
- Temporarily disable your antivirus and/or firewall, then start Mailbird again and see if the issue improves.
- If disabling them resolves the issue, we strongly recommend whitelisting Mailbird in your security software so it doesn't interfere again:
🗂️ Delete Mailbird's Misc Folder
Clearing the local Misc cache folder resolves many freeze and hang issues.
- Close Mailbird completely.
- Open this folder in File Explorer: C:\Users\(UserName)\AppData\Local\Mailbird
- (UserName) is your Windows username (e.g. John Doe).
- Find the folder named Misc.
- Make a copy of the Misc folder and place it somewhere safe (e.g. your desktop) as a backup.
- Delete the original Misc folder from C:\Users\(UserName)\AppData\Local\Mailbird\.
- Start Mailbird again and check if the freezing or hanging has stopped.
⚠️ Known Conflict: FormSwift
A rare but known cause of Mailbird hanging is the FormSwift app. If you have FormSwift installed:
- Disable FormSwift, then restart Mailbird.
- If this resolves the issue, you'll need to keep FormSwift disabled while running Mailbird, as the conflict is on FormSwift's side and outside of our control.
📨 Still Stuck? Contact Support
If none of the steps above help, please create a Support Ticket here so our team can investigate further.
To help us troubleshoot quickly, please include:
- Your version of Mailbird.
- Whether you're seeing a black border around the Compose window (where you write emails).
- Your Mailbird log file. See How to find your log file for instructions.
❓ Need More Help?
Hopefully one of the suggestions above resolved the issue. If not, our Customer Happiness Team is here to help — click here to contact us.