Storage size on disk for large Thunderbird IMAP folders grows disproportionately

Hi there, I've recently had a problem with a couple of client PCs where their Thunderbird profile folder has grown to fill the entire hard drive. In both cases, the rele… (Lesen Sie mehr)

Hi there,

I've recently had a problem with a couple of client PCs where their Thunderbird profile folder has grown to fill the entire hard drive. In both cases, the relevant account folder in the profile's ImapMail dir had grown to over 300Gb. This account takes up 45Gb on the server (where I'm running Dovecot with maildir storage). In another case on both PCs, an 18Gb account had grown to over 90Gb.

Both client PCs are running up-to-date Thunderbird (139.0.2 64bit), one under Windows 10 and one under Windows 11. Both had auto-compact set, with the minimum saving reduced to 100Mb. Both problematic accounts are shared accounts that use a deeply-nested folder structure. In both cases, I was forced to delete and then recreate the these accounts in Thunderbird.

I'm an experienced sysadmin who is also running the mail server, so I am able to provide any extra info needed. Additionally, I accept that these are large email accounts; I'm in the process of setting up an email archive system for the client using Piler. I have read many other reports of outsize Thunderbird data folders; these are usually referring to less than 20Gb. The problems we're having seem to be an order of magnitude larger!

Thanks in advance, P.

Gefragt von sysadmin12 vor 2 Wochen

Letzte Antwort von sysadmin12 vor 3 Tagen

Sent emails

How can I find emails I sent 22/6/2025? They are neither in "sent Emails" nor in "Spam" file?' All files are lost.

Gefragt von chrissi vor 3 Tagen

Change Send From when sending calendar invitation

I have several email accounts. One of these has a calendar linked to Google. I use this for calendar invitations from any of my accounts. However, I need to be able to se… (Lesen Sie mehr)

I have several email accounts. One of these has a calendar linked to Google. I use this for calendar invitations from any of my accounts. However, I need to be able to send calendar invitations from the non-linked account like you can in Outlook. There, each time you add contacts to an invitation, you get an option to send From: Does Thunderbird have this capability? BTW I am not talking about setting default account. I need to be able to select when I create an invitation.

Gefragt von ian82 vor 4 Tagen

Email from Aliexpress are not fully showed in Thunderbird for Android in Dark Theme

Hi, some emails are not readable or better say visible in Thunderbird for Android in Dark Mode. In Light mode it's fully visible (see Screenshots). Is it an issue in Thun… (Lesen Sie mehr)

Hi, some emails are not readable or better say visible in Thunderbird for Android in Dark Mode. In Light mode it's fully visible (see Screenshots). Is it an issue in Thunderbird, or it's a problem of the email format?

Gefragt von nebu kadnezar vor 4 Tagen

Outlook email address shows up as jumbled mess in Thunderbird - Sending and receiving addresses are also swapped

I have two issues that are related to a buggy interaction between Thunderbird and Microsoft's email server. Issue (1) When I send an email with my Outlook email address … (Lesen Sie mehr)

I have two issues that are related to a buggy interaction between Thunderbird and Microsoft's email server.

Issue (1) When I send an email with my Outlook email address (from the Android app or from outlook.live.com, but not Thunderbird), my email address shows up as a jumbled mess in the sent folder on Thunderbird.

It appears to the effect of

IMCEAEX-_O=FIRST+20ORGANIZATION_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+XXXXXXXXXXXXXXXXX+29_CN=RECIPIENTS_CN=XXXXXXXXXXXXXXXX@sct-XX-XX-XXXX-X-msonline-outlook-6f06c.templateTenant

(I have masked some potentially sensitive information).

In the sent folder on my Outlook Android app, my email address looks normal. It also looks fine on a browser in outlook.live.com. However, it's in the sent folder on Thunderbird that my email address is a mess.

Issue (2) When my Outlook email address is involved, the sending and receiving email addresses in the "correspondent" field are swapped in Thunderbird.

There are a couple situations where this swap happens:

  1. Sending an email with my Outlook email account (either through the Android app or outlook.live.com, but not Thunderbird). In my Outlook sent folder on Thunderbird, the "correspondent" field shows my jumbled email address and not the receiving address, such as bob@gmail.com. Likewise, In the inbox of the receiving email account (such as bob@gmail.com) on Thunderbird, the "correspondent" field shows bob@gmail.com and not my Outlook email address.
  2. Sending an email with any other account in Thunderbird to my Outlook email address. In my Outlook inbox on Thunderbird, the "correspondent" field shows my Outlook email address (this time unjumbled) and not the sending email address. However, in the sent folder of the sending email account in Thunderbird, the "correspondent" field shows up correctly (i.e., my Outlook email address).

These two issues are perplexing and probably related. Thank you for any help!

Gefragt von floen vor 1 Woche

Letzte Antwort von floen vor 6 Tagen

Thunderbird for Windows has far more items in Inbox than TB for Android

OK, I give up. As far as I know, my settings for TB for Android are the same as TB for Windows. However, I have 1300 emails in the Inbox in TB for Windows (and can search… (Lesen Sie mehr)

OK, I give up. As far as I know, my settings for TB for Android are the same as TB for Windows. However, I have 1300 emails in the Inbox in TB for Windows (and can search them), but only about 20-30 in TB for android (hopeless for a search). What am i doing wrong?

Gefragt von Tombarkas vor 5 Tagen

Can't determine which filter is affecting my messages

I have a couple of hundred filters and one of them occasionally kicks in and unexpectedly moves certain messages to a new folder but I can't figure out which filter it is… (Lesen Sie mehr)

I have a couple of hundred filters and one of them occasionally kicks in and unexpectedly moves certain messages to a new folder but I can't figure out which filter it is. Rather than me going through every filter manually, can't Thunderbird tell me which filter affected a given message? I'd like to be able to right-click a message and be shown the exact filter(s) which affected it.

Gefragt von mozilla448 vor 5 Tagen

Letzte Antwort von mozilla448 vor 5 Tagen

Archiving a message in my Feed accounts moves to email account

Updated from 138.xx to 139.02 today. Archiving from either of my two feed (RSS) accounts doesn't work right. I click archive button, instead copies to the archive folde… (Lesen Sie mehr)

Updated from 138.xx to 139.02 today.

Archiving from either of my two feed (RSS) accounts doesn't work right. I click archive button, instead copies to the archive folder of first email account in list.

Used troubleshooting mode to disable addons, still happens. Saw nothing in changelog to explain this.

A bug?

Gefragt von ownedbycats vor 5 Tagen

No messages found

Since 5.18.2025 I get a "no message found" in my sent folders and other folders. "Find" will still find the messages and they can be opened, but I can't get the email fo… (Lesen Sie mehr)

Since 5.18.2025 I get a "no message found" in my sent folders and other folders. "Find" will still find the messages and they can be opened, but I can't get the email folders to display. I know they are still there. Version 128.10.2esr. How can I get them to display in the folders?

Gefragt von Robert Corbett vor 1 Monat

Letzte Antwort von Robert Corbett vor 5 Tagen

How can I build an incremental backup of a webmail account ?

Can I use Thunderbird to build an incremental local backup/archive of all messages transiting (incoming/outgoing) a webmail account ? Any idea how to achieve this&n… (Lesen Sie mehr)

Can I use Thunderbird to build an incremental local backup/archive of all messages transiting (incoming/outgoing) a webmail account ?

Any idea how to achieve this ?

My problem is:

  • A POP3 account will miss all folders except the Inbox. (It's a pity that POP4 has not gained traction yet.)
  • An IMAP account creates a mirror, not a backup. Remote deletions in the webmail account must not delete messages from my backup and vice versa.

detailed requirements:

  • one-way sync only, since a local backup/archive must be built, not a mirror (two-way synchronization):
    • Remote deletions must not cause local deletions (otherwise it would be a mirror, not an archive/backup).
    • Local move/delete operations must not be reflected back to the mail server.
    • Read‐only access to the mail server: no moves, deletes or flags remotely.
  • All messages in all folders must be included in the backup: Inbox, Sent, custom folders, etc. Since POP3 can only back up the Inbox, I will probably have to settle for IMAP to include all folders.
  • No duplicates: Messages must not be stored locally more than once.
  • Messages must be stored as full offline copies locally (not just headers).

Gefragt von welcome vor 1 Woche

Letzte Antwort von welcome vor 5 Tagen