If your Thunderbird is not searching, is stuck, and is not returning a proper result. You must follow this guide to rebuild Thunderbird index (Global & Folder Level) to improve performance and sync the Thunderbird search index with emails.
Key Takeaways
- Thunderbird has a Global Search index (global-messages-db.sqlite) & Local Index (.msf Files)
- Thunderbird auto-rebuilds the Global search index with Gloada upon deleting from the profile & restarting.
- The repair folder option force recreates the Thunderbird’s local index.
What is Thunderbird Index & its Types?
Mozilla Thunderbird email client stores all email metadata like subject, date, to, from, CC/BCC, read/unread status, etc., in a separate folder called Index.
Keeping metadata separately in Thunderbird makes searching, opening the folder, and sorting email messages in Thunderbird much faster.
Types of Thunderbird Indexes
There are 2 types of indexes in Thunderbird that users want to rebuild: Global Index and Local Index. Here is a quick comparison between them :
| Aspect | Folder / Local Index | Global Index |
| Scope | Each mailbox folder has its own local index | Single search index for the entire Thunderbird data |
| File type | Saved in MSF format | Saved in SQLite format |
| Indexed data | Only stored email metadata | Email metadata plus address books |
| Used for | Basic folder opening and sorting | Centralized global search |
When Should You Rebuild Thunderbird Index?
Rebuilding or Resetting Thunderbird search index means deleting the old/existing Thunderbird index and replacing it with a new & fully synced index. Here are practical situations when force rebuilding the Thunderbird index is beneficial:
- If your Global Search (Ctrl+Shift+K) is slow or not working.
- You can open emails in Thunderbird folders, but you are not able to search them.
- Thunderbird displays an incorrect read/ unread message count.
- When you see deleted or archived emails in the active folders.
- When Ghost Messages (emails that appear in the message list can’t be opened or read) frequently show up.
- In case the Thunderbird index is corrupted after migration.
Rebuilding the index of all Thunderbird folders also boosts the speed of search and automatically fixes corruption caused by a crash or force close.
Thunderbird Rebuild Global Search Index: Step-by-Step
Thunderbird enables you to rebuild the search index very easily. To rebuild the Thunderbird index, a user must clearly understand the profile location of their data.
Thunderbird Profile location on Mac & Windows:
- Win: C:\Users<username>\AppData\Roaming\Thunderbird\Profiles\
- Mac: /Users/<username>/Library/Thunderbird/Profiles/
Follow the steps to reset Thunderbird Global Index:
- Close Mozilla Thunderbird.
- Go to the Thunderbird profile folder on your computer.
- Open the default-release folder.
- Scroll down and look for global-messages-db.sqlite.
- Right-click and delete the global-messages-db.sqlite.
- Restart Thunderbird, and rebuilding will automatically start.
How to Verify Thunderbird Rebuild Index?
- In Thunderbird, go to the Navigation menu.
- Go to Tools and Activity Manager to verify the rebuild.
Note: Rebuilding Thunderbird is not instantaneous. It can take even hours to rebuild, depending on the mailbox size.
How to Rebuild Thunderbird Index – Local/ Folder Level?
There are 2 easy ways in which users can rebuild the local/folder-level Thunderbird index.
Method 1: Delete Folder-Level MSF Files in an Account to Rebuild Index
- Go to the Thunderbird profile location on your PC.
- Look for the IMAPMail Folder.
- Open each Imap.account.com folder at a time.
- Delete the files ending with .msf.
- Restart Thundebird to rebuild the index of Thundebird’s all folders.
Method 2: Inbuilt-Option to Rebuild Thunderbird Index (MSF Index)
Thunderbird natively offers a Repair folder option to quickly rebuild the Thunderbird Index without you having to manually modify the profile folder.
- Launch the Thunderbird application.
- Select the folder you want to rebuild the index for.
- Right-click and Choose Properties.
- Click on Repair Folder and Press OK.
Deleting the MSF Files can be risky; this option is the expert-recommended way to safely rebuild the Thunderbird index.
Note: Rebuilding the Global index does not automatically rebuild the index of all folders. You have to do them one at a time.
What if the Thunderbird Rebuild Index is Not Enough?
If you have rebuilt Thunderbird index (Local & Global) successfully and still face issues with indexing, search, and sorting. It is likely due to a much deeper issue caused by Thunderbird Profile Corruption.
Always back up Thunderbird profile data to prevent any kind of email data loss due to profile corruption or accidental deletion. Download the Thunderbird Backup Tool today to safeguard your Thunderbird profile data with contacts & calendar. Free Trial is also available.
FAQs: Rebuild Thunderbird Index
Q1: Does each Thunderbird folder have its own index?
Yes, Thunderbird stores email metadata in all folders separately in a distinct .msf file called local index.
Q2: Can I use the same process to rebuild Thunderbird’s search index in all versions?
Yes, this method helps you rebuild and fix indexing issues across all the latest Thunderbird versions.
Q3: Will rebuilding the index delete my emails?
No, rebuilding does not after the email stored in the Thunderbird profile.
Q4: Why does Thunderbird keep re-indexing every time it starts?
This is likely due to a corrupt Global Thunderbird Index; Thunderbird force rebuild index to fix the issue.
Concluding Notes
Rebuilding Thunderbird’s Global or Local index is a reliable way to speed up search and fix related issues. This guide explained how to force rebuild Thunderbird index manually on both Mac & Windows devices without any modification to the email data. However, if you still have issues with Thunderbird’s indexing. Reach out to our Technical support team available 24/7 worldwide to fix the issue.