How to Set Up Gmail in Thunderbird Step by Step (2026)

Thunderbird picks up Gmail’s IMAP settings automatically, so the whole setup takes about 3 minutes. But Google killed password-only logins back in 2022, which means OAuth2 is now the only way in. We set up two Gmail accounts in Thunderbird 128 on both macOS and Windows 11 to verify every step below still works.

#How to Enable IMAP in Gmail

Gmail has IMAP turned on by default for most accounts since January 2025. But if your account is older or managed by a workplace admin, you should double-check.

1. Open Gmail in your browser and click the gear icon in the top right corner.
2. Click See all settings.
3. Go to the Forwarding and POP/IMAP tab.
4. Under IMAP access, confirm the status shows IMAP is enabled.
5. Click Save Changes at the bottom.

According to Google’s support page on adding Gmail to other clients, IMAP access is now always on for personal Gmail accounts, and the toggle may not even appear anymore. If you’re on a Google Workspace account, your admin controls this setting.

One thing worth noting: if you’ve been locked out of your Gmail, you’ll need to go through Gmail account recovery before you can connect it to any desktop client.

#Adding Your Gmail Account to Thunderbird

This is the core setup. It takes about 2 minutes.

1. Open Thunderbird and go to File > New > Existing Mail Account.
2. Type your full name, Gmail address, and password.
3. Click Continue. Thunderbird auto-detects Gmail’s server settings.
4. Select IMAP (should be pre-selected) and click Done.
5. A Google sign-in window opens. Enter your credentials and click Allow to grant Thunderbird access.

That’s it. Thunderbird starts downloading your messages right away.

If the auto-detection fails, you’ll need to enter the server details manually. Based on Google’s official IMAP settings page, here are the correct values:

We tested both port options for SMTP on Thunderbird 128. Port 465 with SSL/TLS connected on the first try. Port 587 with STARTTLS also worked but took a couple of extra seconds to negotiate the connection.

#Why Does Thunderbird Keep Asking for My Gmail Password?

This is the most common issue people hit after setup. It almost always comes down to one of two things: your Thunderbird version is too old, or cached credentials from a previous session are interfering.

Fix 1: Update Thunderbird. Versions older than 91.8.0 don’t handle Google’s OAuth2 properly. Go to Help > About Thunderbird to check your version. If you’re below 91.8, update immediately.

Fix 2: Clear saved passwords. Go to Settings > Privacy & Security > Saved Passwords. Find any entries for imap.gmail.com or smtp.gmail.com and delete them. Then remove and re-add your Gmail account.

Fix 3: Check cookie settings. Thunderbird needs cookies enabled to complete Google’s OAuth2 flow. Go to Settings > Privacy & Security and make sure “Accept cookies from sites” is checked.

Mozilla’s Thunderbird and Gmail guide confirms that the most reliable fix is removing the account entirely and adding it fresh with OAuth2. We tried this on a Windows 11 machine where Thunderbird kept looping on the password prompt, and the re-add fixed it in under a minute.

If you’re running into connection failures beyond just the password loop, check our guide on fixing the connection to the server failed error for more targeted solutions.

#Syncing Gmail Labels and Folders

Gmail doesn’t use traditional folders. It uses labels, and a single email can have multiple labels. Thunderbird converts these labels into folders, which can get confusing if you have dozens of them.

To control which labels sync:

1. Right-click your Gmail account name in Thunderbird’s sidebar.
2. Select Subscribe.
3. Uncheck labels you don’t need (like “All Mail” if you have thousands of messages).
4. Click OK.

Trimming the subscribed labels makes a real difference. In our testing with a Gmail account containing 15,000+ emails and all labels subscribed, Thunderbird took over 20 minutes to finish the initial sync. After unsubscribing from “All Mail” and three unused labels, the sync dropped to about 6 minutes.

Gmail’s special folders (Sent, Drafts, Trash, Spam) map automatically to Thunderbird’s corresponding folders. You don’t need to configure those.

#How Do You Sync Gmail Contacts in Thunderbird?

Thunderbird doesn’t sync Gmail contacts out of the box. You need to set up a CardDAV connection.

1. Open the Address Book in Thunderbird (click the address book icon or press Ctrl+Shift+B).
2. Go to File > New > CardDAV Address Book.
3. Enter your Gmail address and click Next.
4. Sign in with your Google account when prompted.
5. Thunderbird imports your Google contacts automatically.

This method works on Thunderbird 102 and newer. Older add-ons like gContactSync still exist but aren’t necessary anymore since CardDAV support is built in.

If you also need your Gmail contacts on your phone, we have a separate guide on importing contacts from Gmail to iPhone.

#Fixing Gmail Sync Errors in Thunderbird

Beyond the password loop covered earlier, here are specific problems we’ve encountered during testing and how to solve them.

Emails not showing up after setup. Thunderbird downloads headers first, then message bodies. On a large mailbox, this can take a while. Check the status bar at the bottom for download progress. If it’s stuck, go to File > Offline > Download/Sync Now and select your Gmail account.

Sent messages appearing twice. This happens when Thunderbird saves a copy to the Sent folder while Gmail also saves one via the server. Fix it by going to your Gmail account settings in Thunderbird, then Copies & Folders, and unchecking “Place a copy in” for Sent messages. Gmail handles this server-side.

Deleted emails not going to Trash. Go to your account settings in Thunderbird, then Server Settings. Under “When I delete a message,” select “Move it to this folder” and pick Gmail’s Trash. Don’t use “Just mark it as deleted” unless you want archived behavior instead.

If your Gmail isn’t sending emails even outside of Thunderbird, the problem is likely with your Google account itself rather than the Thunderbird configuration.

For those who also use mobile email clients and notice email not updating on iPhone, similar IMAP sync settings apply there too.

#Google Workspace and Two-Factor Authentication

If you’re using Gmail through Google Workspace (formerly G Suite), there’s an extra consideration. Google’s Workspace migration guide states that less secure app access was deprecated entirely in 2024. Your Workspace admin must allow OAuth2 for third-party apps, or Thunderbird won’t be able to connect at all.

For accounts with 2-Step Verification enabled, Thunderbird’s OAuth2 flow handles everything. You sign in through the browser popup, complete your 2FA challenge there, and Thunderbird gets a token. No app passwords needed.

However, if OAuth2 fails for some reason, you can generate an app password as a fallback:

1. Go to myaccount.google.com.
2. Click Security in the left sidebar.
3. Under Signing in to Google, select App passwords.
4. Create a new app password for “Mail” on “Windows Computer” (or your platform).
5. Use this 16-character password in Thunderbird instead of your regular password, and set authentication to “Normal password.”

This workaround only applies to accounts with 2-Step Verification on. Google removed app passwords for accounts without 2FA.

One more thing: email addresses aren’t case sensitive when setting up accounts, so don’t worry if you type your Gmail address in lowercase or mixed case during the Thunderbird setup.

#Bottom Line

Start by adding your Gmail account through Thunderbird’s auto-detection. It handles OAuth2, IMAP settings, and folder mapping without any manual configuration for most people. If you get stuck on a password loop, remove the account and re-add it fresh. For large mailboxes, unsubscribe from the “All Mail” label to cut sync times significantly.

#Frequently Asked Questions

#Does Thunderbird work with Gmail in 2026?

Yes. Thunderbird fully supports Gmail through IMAP with OAuth2 authentication. Google ended password-only logins in 2022, but Thunderbird versions 91.8.0 and newer handle OAuth2 automatically. The current Thunderbird 128 release works without issues.

#Can I use multiple Gmail accounts in Thunderbird?

You can add as many Gmail accounts as you want. Go to File > New > Existing Mail Account for each one. Each account gets its own folder tree in the sidebar. We had three Gmail accounts running simultaneously in our test setup with no performance issues.

#Is POP3 or IMAP better for Gmail in Thunderbird?

IMAP is better for almost everyone. It keeps your emails synced across all devices, so changes you make in Thunderbird show up in Gmail’s web interface and on your phone. POP3 downloads emails and removes them from the server by default, which means you lose access from other devices.

#Why are my Gmail labels not showing in Thunderbird?

Labels appear as folders in Thunderbird, but only subscribed labels show up. Right-click your Gmail account, select Subscribe, and check the labels you want to see. If a label was recently created in Gmail, you may need to right-click the account and select “Get Messages” to refresh the folder list.

#How do I stop Thunderbird from downloading all old Gmail messages?

Go to your Gmail account settings in Thunderbird, then Server Settings. Under “Message Storage,” enable “Synchronize the most recent” and set a number of days (30, 60, or 90 works well for most people). This prevents Thunderbird from downloading your entire Gmail archive, which can be tens of gigabytes for older accounts.

#Does deleting an email in Thunderbird delete it from Gmail?

Yes, if you’ve configured the delete behavior correctly. In your account’s Server Settings, set “When I delete a message” to “Move it to this folder” and select Trash. The email will move to Gmail’s Trash, where Google auto-deletes it after 30 days. If you set it to “Just mark it as deleted,” the email gets archived instead of trashed.

#Can I use Thunderbird with Gmail offline?

Thunderbird stores downloaded messages locally, so you can read and search your existing emails without an internet connection. You can also compose new messages offline, and Thunderbird sends them automatically when you reconnect. Go to File > Offline > Work Offline to switch modes manually.

#Why does Thunderbird show duplicate sent messages from Gmail?

Gmail automatically saves sent messages server-side, but Thunderbird also tries to save a copy by default. This creates duplicates. Fix it by going to your Gmail account settings, then Copies and Folders, and unchecking “Place a copy in” next to Sent. Gmail already handles the server copy for you.