Discover solutions for common issues and explore best practices to diagnose and resolve problems.

Mozilla Crash Reporter TB

The Mozilla Crash Reporter dialog box appears when Thunderbird crashes and lets you send a crash report. Learn how it works and how to access your crash reports.

Thunderbird Thunderbird Last updated: 2 weeks ago

Rebuilding the Global Database

Rebuilding the Global Database will initiate a re-indexing of emails and address book cards (newsgroup messages are not indexed).

Thunderbird Thunderbird Last updated: 08/28/2018

Cannot send messages

If you cannot send messages with Thunderbird, this page provides a series of steps you can follow to check for common problems.

Thunderbird Thunderbird Last updated: 12/28/2023

Troubleshoot Mode Thunderbird

How to use Thunderbird's Troubleshoot Mode to find and fix problems, especially if they are caused by add-ons.

Thunderbird Thunderbird Last updated: 11/24/2023

Cannot delete messages

This article explains how to fix issues with message deletion caused by a missing or corrupted trash folder.

Thunderbird Thunderbird Last updated: 07/14/2017

I'm having problems confirming my Mozilla account

Here are some common solutions to help you resolve issues such as missing confirmation emails and outdated or locked Mozilla account status.

Firefox, Mozilla Account Firefox, Mozilla Account Last updated: 3 weeks, 5 days ago

Why do I get an error when I try to upgrade my subscription?

Users who purchased a subscription from the Apple Store or Google Play Store will receive an error message when attempting to upgrade their subscription from the website. This article explains what the error means and how to fix it.

Firefox Relay, Mozilla VPN Firefox Relay, Mozilla VPN Last updated: 11/16/2022

FAQ Changing IMAP to POP

If your mail server supports both IMAP and POP, Thunderbird will use IMAP by default. Use these instructions to manually configure a POP account.

Thunderbird Thunderbird Last updated: 07/17/2018

Cannot receive messages

If you cannot receive messages, this page provides a series of steps you can use to check for common problems.

Thunderbird Thunderbird Last updated: 12/28/2023

Some videos won't play in background

Some popular video websites have changed their settings on the server side so that videos will no longer play in the background.

Firefox for Android Firefox for Android Last updated: 05/15/2017

What happened to Firefox Send?

Firefox Send has been discontinued as of September 17th, 2020. Thank you for trying Firefox Send in the past.

Firefox, Firefox Send Firefox, Firefox Send Last updated: 07/04/2023

Disable Firefox Sync on a lost phone or tablet

This article describes what you should do to prevent someone from accessing your passwords on a lost device with Firefox Sync.

Firefox, Firefox for Android, Firefox for iOS,... Firefox, Firefox for Android, Firefox for iOS, Mozilla Account Last updated: 10/29/2023

Hyperlinks in Messages Not Working

When clicking hyperlinks in email, your default web browser should open and display their content. Learn why that may fail and why links may not be clickable.

Thunderbird Thunderbird Last updated: 10/07/2021

Sign up for Pocket with your Mozilla account

Pocket for Firefox lets you save articles for later. All you need is a free account. Sign up or sign in with your Mozilla account.

Firefox, Mozilla Account, Pocket Firefox, Mozilla Account, Pocket Last updated: 10/23/2023

End of support for Firefox Lockwise

Mozilla ended support for the Firefox Lockwise app on Android and iOS, effective December 13, 2021, and integrated its functionality into Firefox mobile.

Firefox Lockwise Firefox Lockwise Last updated: 1 week, 3 days ago

Sign in to Pocket with your Mozilla account

Learn how to sign in to Pocket with your Mozilla account and resolve issues with signing in.

Firefox, Mozilla Account, Pocket Firefox, Mozilla Account, Pocket Last updated: 10/23/2023

Uninstall Firefox for iOS

If Firefox isn't for you, uninstalling it from your iOS device only takes a few seconds.

Firefox for iOS Firefox for iOS Last updated: 08/21/2023

How to obtain the Mozilla VPN Logs

When troubleshooting issues with Mozilla VPN, our engineers can ask for logs. These don't contain any personal information, but give hints about the issue.

Mozilla VPN Mozilla VPN Last updated: 3 weeks, 1 day ago

Profiling Thunderbird Performance

How to create a Thunderbird performance profile to find causes of high CPU load or slowness.

Thunderbird Thunderbird Last updated: 03/02/2024

Firefox for iOS won't load web pages

If a website isn’t loading even after you’ve checked the Internet connection, here are a few things you can try.

Firefox for iOS Firefox for iOS Last updated: 10/15/2022

How do I reset Mozilla VPN?

This article explains how to clear Mozilla VPN app data from your device.

Mozilla VPN Mozilla VPN Last updated: 1 week, 2 days ago

Enable or disable Local Network Access on iOS

LAN Bypass allows you to control whether or not your device can access devices on the local network while the VPN is on. Examples of these can be your network printer, your smart TV, AirDrop and CarPlay.

Mozilla VPN Mozilla VPN Created: 05/08/2024

Firefox is stuck in Troubleshoot Mode

Learn why Firefox may start in Troubleshoot Mode (previously known as "Safe Mode") when you expect it to start normally and how to fix it.

Firefox Firefox Last updated: 03/11/2023

Problems with email and how to find help

Find out the right direction to get help using webmail in Firefox and links to support pages for popular web-based email services.

Firefox Firefox Last updated: 06/22/2015

Avoid crashes - Tips and tricks

Here are some easy things you can do to avoid crashes and keep Firefox running in tip-top shape.

Firefox Firefox Last updated: 09/21/2021

Latest Firefox issues

This article links to solutions for the latest Firefox issues like problems with Flash not loading or crashing.

Firefox Firefox Last updated: 03/05/2015

Firefox keeps crashing at startup

If Firefox keeps crashing when you try to start it and other solutions don't work, a clean reinstall can often fix the problem.

Firefox Firefox Last updated: 11/09/2022
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