How to Compress Thunderbird Email Files in 2023?

Rollins Duke   
Published: September 14th, 2023 • 6 Min Read

As Thunderbird is a free and open-source email client with premium features, several computer users use it for sending and receiving email messages. After several years of use, Thunderbird keeps asking to compact folders by showing a popup message.

If you are also receiving a message to compact Thunderbird mailbox folders, then you will need to compress Thunderbird email files. Continue reading to discover various techniques for compressing Thunderbird email, folders, headers, and more.

compact now

When the capacity for additional data storage is met, the Thunderbird compact folders prompt is shown. Thunderbird Compact prompt has several options, let’s understand them.

  • Compact Now: Just click the ‘Compact Now’ button to start Thunderbird folders compacting instantly. You can also enable the ‘Compact folders automatically in the future’ option if you think this is beneficial for you.
  • Learn More: Hit the ‘Learn More’ button and read detailed information about compacting (purging) from the official website.
  • Remind Me Later: Choose the ‘Remind Me Later’ option if you think the prompt arrived at an inopportune moment.

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What Are Thunderbird Compact Folders?

In Thunderbird, compacting is an effective file maintenance process that allows users to reclaim disk space without deleting any emails. It is also known as purging and Thunderbird has inbuilt features to compress Thunderbird email folders.

When you delete emails in Thunderbird, they are marked as deleted or moved, and will no longer be visible in the application. To remove the emails permanently, you must compact the Thunderbird folders.

Read Similar: How to Reduce Mail Storage on MacBook?

Techniques to Compress Thunderbird Email Folders?

There are several methods available for compressing Thunderbird folders and headers. We are providing comprehensive instructions for each technique, with three types of solutions in total Inbuilt, Add-ons, and Third party.

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1st Method: Compact A Thunderbird Folder

    1. Start the Thunderbird application on your computer.
    2. Select a Thunderbird folder that you want to compact.
    3. Right-click on the folder and choose the ‘Compact’ option.
      compact thunderbird folder
    4. See the message ‘Done compacting (approx 280 KB saved)’.
      done compacting
    5. Select another Thunderbird folder for compacting.

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2nd Method: Compact All Thunderbird Mailbox Folders

  1. Launch Thunderbird on your computer.
  2. Choose the ‘File << Compact Folders’ option.
    compact all thunderbird folders
  3. Wait for purging your Thunderbird folders.
  4. All Thunderbird folders compacted successfully.

3rd Method: Configure Thunderbird for Automated Mailbox Compression

  1. Run the Thunderbird email client on your machine.
  2. Select the ‘Tools << Account Settings’ option.
    account settings
  3. Choose ‘Disk Space’ and set up it for automation.
    disk space
  4. Setup it for deleting all messages instead of recent ones.
  5. Setup to delete messages more than preferred days old.

4th Method: Use Compact Headers Add-ons for Thunderbird

  1. Download Thunderbird Compact Header Add-On for free.
    compact headers add ons
  2. Open your Thunderbird and choose ‘Add-ons and Themes’.
    add ons and themes
  3. Thereafter, click the ‘Gear’ icon.
    gear icon
  4. Select the ‘Install Add-on from File…’ option.
    install add on from file
  5. Choose download Add-on setup XPI file and choose ‘Open‘.
    select compact header add on file
  6. Do you want to Add a Compact Header? Press the ‘Add’ button.
    add thunderbird compact add ons
  7. Compact Header was added, hit ‘Ok’.
    compact headers added
  8. Select an email and right-click on it.
    hide headers
  9. Choose the ‘Hide Headers’ option and Finish.

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5th Method: BitRecover Software to Compress Thunderbird Emails

BitRecover MBOX Compress Wizard is a perfect software to compress Thunderbird mailbox folders. You can export MBOX files from Thunderbird for free using the ImportExportTools NG addon. Thereafter, use this software to compress Thunderbird mailbox files.

You can also go to Thunderbird’s default storage location to get MBOX files.

Thunderbird POP Account:

C:\Users\admin(Username)\AppData\Roaming\Thunderbird\Profiles\2zy47dr1.default-release-1(Account or Edition Name)\Mail

Thunderbird IMAP Account:

C:\Users\admin(Username)\AppData\Roaming\Thunderbird\Profiles\2zy47dr1.default-release-1(Account or Edition Name)\ ImapMail

Afterward, use the recommended software to compress your Thunderbird database, including emails and headers. Once the MBOX file is compressed, you can then complete the process by importing the MBOX into Thunderbird.

Thunderbird Compress Software specializes in file compression, offering users the ability to reduce the size of their Thunderbird mailbox through the use of 3 preferences. It stands out from alternatives with its extraordinary features.
compress thunderbird email files

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Thunderbird Compress Tool Vs Other Alternatives

BitRecover Solution Other Solutions
It is suitable to reduce enough space in the Thunderbird profile. Alternatives are only suitable to decrease a few MB or KB spaces.
Thunderbird Compress Software has 3 choices to compress or compact Thunderbird mailboxes. Manual methods of purging Thunderbird mailboxes do not offer a range of options.
This software provides separate options to extract and remove Thunderbird attachments. You can only extract attachments from Thunderbird but there is no option to remove them.
If your Thunderbird application has crashed and is no longer functioning, there may be an available solution. If you wish to use the manual method, it is important to ensure that Thunderbird is functioning correctly.
This software is user friendly and features a straightforward graphical user interface. Non-technical users may find these processes complicated due to the technical nature of the requirements.
This software is suitable for all Thunderbird editions. Manual techniques may be different according to Thunderbird versions.

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Some Frequently Asked Questions

Ques 1: When do I compress Thunderbird email files?

Ans: If your Thunderbird is working slowly and asking to compact folders again and again. Then you need to compact Thunderbird mail folders.

Ques 2: Does your software allow to compact Thunderbird headers?

Ans: Our developers specially added a separate feature to compact Thunderbird mailbox folders quickly.

Ques 3: Can I use your software to compress Thunderbird 102.10.0 latest edition?

And: Yes, Thunderbird Compress Software is suitable for the latest and old Thunderbird versions.

The Final Thoughts

We have reviewed the top five methods for compressing Thunderbird email files, folders, and headers. Depending on your needs, you can select a suitable technique. If your Thunderbird is close to exceeding the email size limit, then the Thunderbird compression tool is the most fitting solution for reducing mailbox size.

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