How To Speed Up Thunderbird By Archiving Emails

Martin Brinkmann
Sep 17, 2010
Software, Thunderbird, Windows

Most desktop email clients have one big problem, that becomes apparent over time: They do not offer email archiving or backup options. This means that the email databases will increase with every email, which in turn can have an impact on the performance of the email software. It should be obvious that it takes longer to load an email folder with five thousand emails, than one with ten.

The main purpose of email archiving and backup software is to offer fallback copies if the emails and mailboxes in case they get corrupted or deleted on the main storage device. Many desktop email client users do not backup their mail databases regularly, which can end in disaster if the mailboxes get corrupted. The same applies to companies and businesses, but with dire consequences.

As a side effect, archived emails can be moved to another storage device or server, so that they free up disk space on the hard drive that the email client uses to store the email database.

Today we are going to show you how to speed up the email client Thunderbird, by archiving part of the stored emails. The idea is to combine backing up emails regularly, with the benefits of being able to remove emails from the email client that are old and not needed on a regular basis. In case they are needed they can still be accessed in the archiving software.

Before we start, we are going to create a full backup of the Thunderbird profile with MozBackup. Just download and run the backup software, and select to backup the Mozilla Thunderbird profile. Make sure all data is included in the backup (default settings).

backup email client
backup email client

The program can later be used to restore the full Thunderbird profile in case that is needed.

Windows users have the option between several email archiving programs. For the purpose of this tutorial, we are going to use Mailstore Home. The program makes it almost foolproof to archive emails from various email clients, including Thunderbird, Windows Live Mail, Microsoft Outlook, Google Mail and general IMAP and POP3 mailboxes. The program includes options to search and read emails directly in its interface.

mailstore home
mailstore home

It takes only a few clicks to archive emails in MailStore Home. A click on Archive E-Mail opens the archiving page of the software. Here it is possible to select an email client or protocol from the list to launch a wizard.

The e-mail archiving wizard looks like this for Thunderbird users:

Selection of the Thunderbird profile:

The default profile is the standard profile. Most users will probably only have the default profile, unless they are working on a multi-user computer.

archive mozilla thunderbird
archive mozilla thunderbird

Customization of the archiving options:

Here it is possible to select all email folders for backup, or only specific ones. It is furthermore possible to filter emails by data or status.

archive emails thunderbird
archive emails thunderbird

The archiving can take some time, depending on the number of emails stored in the Thunderbird mailboxes. MailStore Home displays the saved profiles in a listing on the archive e-mail page. The program saves all information, including email attachments and headers in its interface.

We suggest to archive all emails on the first run. This is important as it makes it easier to delete emails in the email client afterwards. Delete emails? Yes, to speed up Thunderbird emails need to be removed from the client.

The next step depends on the user and the folder structure. A user only working with the inbox may want to delete all emails older than a specific age, and do the same in the sent, trash and junk folders. This should reduce the size of the mailboxes considerably in the email client.

Finally it is important to compact the folders after deleting the emails in the mail client. Like other email clients, Thunderbird does not physically remove the emails from the mailboxes after they are deleted by the user. This is done by compacting the folders.

The option is available under File > Compact Folders. Before it is selected, a folder in the mail structure needs to be selected.

Hint: It is possible to configure Thunderbird to automatically compact folders by clicking on Tools > Options, switching to the Advanced tab, there to the Network & Disk Space tab, and enabling Compact folders when it will save over x KB.

Thunderbird may start up and feel noticeably faster after archiving and deleting emails in the client. This largely depends on the amount of mails that have been stored in the client prior to the operation. A user with a few hundred mails will probably not notice a speed improvement at all, while a user with tens of thousands of emails likely will.

Do you archive or backup your emails? Let us know in the comments.


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  1. Anonymous said on March 9, 2023 at 1:52 pm

    Does it come back after every “moment” update?

  2. Baloney said on March 9, 2023 at 2:23 pm

    Yeah right.. Like this is going to stop defender from running =) This is comedy gold right here.

  3. Anonymous said on March 9, 2023 at 3:25 pm

    no ‘about the author’ paragraph?

  4. Gregory said on March 9, 2023 at 4:19 pm

    For permanent disable defender is if removed complete from system no just change permission folder.

    Just this is joke.

  5. moi said on March 9, 2023 at 5:57 pm

    simpler, load Autoruns (SysInternals)
    – filter “Defender”
    – untag all entries
    – reboot
    nothing has changed since my 1st modification years ago

  6. John G. said on March 9, 2023 at 6:32 pm

    I wouldn’t disable Defender imho, it has too many hidden roots inside Windows itself. One time I tried to uninstall it using brute force scripts and then the Onedrive feature stopped working definitely. A reinstallation was needed and since those times I prefer to maintain Defender untouched. It’s a better method to install another antivirus and it will disable Defender in a safer and easier mode (e.g., Avast is the best in this way, and also Panda Cloud Free is good too).

    1. Tweakmaster said on September 29, 2023 at 9:57 am

      U are just * [Editor: removed] thats the problem ;p first of all u shall always debloat windows u shall have max 65 services with your drivers for pc and windows own servs. You didnt know what that script did

  7. boris said on March 10, 2023 at 12:19 am

    You can not stop defender from running in background or remove it without some penalty. All you can do is to limit telemetry.

    1. TelV said on March 10, 2023 at 4:52 pm


      It’s probably Smartscreen which is preventing WD from being disabled. Get rid of that and the problem should be solved:

  8. hoho said on March 10, 2023 at 1:47 pm

    Remove Windows and go for Linux.

    1. basingstoke said on March 10, 2023 at 2:51 pm

      Linux sucks dude. Besides it’s not comparable to Windows, these OSes are in different classes entirely.

      1. Derp said on March 10, 2023 at 4:36 pm

        I use Linux as my daily driver. It’s far more stable than Windows. When’s the last time you used Linux, 2010?

      2. Bromosexual said on March 11, 2023 at 2:04 am


        You’re right, dude. Bro, linux is just a bunch of code that starts before the OS, dude. Brobrodude, that shit ain’t even got emojis, dudebrodudeman! Dudebro, it’s no way near as cool as Windows with its hardcoded abilities to make money off the user, bro. Yo brodude man, you’re the coolest dude ever man, bro. Dude.

      3. basingstoke said on August 16, 2023 at 7:20 pm

        Lol what? Windows 7 doesn’t come with any Emojis

  9. TelV said on March 10, 2023 at 4:46 pm

    Download Autoruns and remove the checkmark from Windows Defender. It doesn’t remove it, but it will never run.

  10. Simon said on March 10, 2023 at 8:37 pm

    Just use “Defender Control”:

    Per this video,
    it also works on Windows 11 too…

  11. Someone said on March 10, 2023 at 9:26 pm

    Win Defender, is completly the most succesful free-built in antivirus of Microsoft. Really nice product. Saved my ass a lot of times. Has updated malware database, completly strong defence
    from whatever smart screen disables. Or if you want better and more upgrated (paid) program,
    you can go further. But defender is always on your side.

  12. CalixtoWVR1 said on March 10, 2023 at 10:03 pm

    Why would one disable Windows (or Microsoft) Defender in the first place?. I consider this to be playing with fire big time. Everybody knows that if one is using another A-V, Defender will be disabled on its own and won’t be in one’s way.

  13. Ed D said on March 10, 2023 at 11:09 pm

    Why would I want to disable Windows Defender in the first place? It’s a great anti virus in my opinion. Been using it since Windows 8 and and never had a problem or a virus. Why mess with a good thing, if it ain’t broke don’t fix it.

  14. owl said on August 17, 2023 at 1:57 am

    How a ridiculous article!
    I am thoroughly stunned.

    Why Should You Disable First-Party Windows Defender?
    I can only think that it is “malice or perversely intention (want you to buy a third-party AV where you can expect a back margin)” to guide invalidation without showing the premise.
    No sane company will use third-party closed source programs (such as AV).

    As I thought, “Ghacks Technology News” seems to be coming to downfall.

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