Thunderbird Community Forum

My tags stopped working, right click -> Tag no longer has the list of tags, although 'Manage Tags' shows my list of tags and 'New Tag' applies the tag to the selected message, but no tags appear on right click-> Tag list. I'm using Mac OS Version 15.5 and Thunderbird 139.0.2 and have rebooted and reinstalled Thunderbird to no effect. Thanks for any help you may have!

Cannot delete e-mails from inbox. Cannot move them to Trash. Will copy only a few into trash and not remove them from the inbox. Emptied trash, compacted inbox. Read your suggestions, not help. Using Windows 10, latest version, Thunderbird 139.0.2.

Please how do I recieve my new emails in decending order I am finding new emails at the bottom of the pile and I have to scroll down all my old ones to get to new...thank you for your time

Certificate errors have been an ongoing, several-times-a-day frustration for me and other users, with different ISPs, since approximately June 25. Is anyone working on this bug? Because it clearly is a bug: Not only I but several other users have reported that Thunderbird worked fine until that date, then stopped working fine. What changed, and can it be put back the way it was, or can we receive some explicit instructions on how to fix it for ourselves? It's making Thunderbird borderline unusable. Every time I try to send a message, I have to confirm a security exception, then send it again. Several times a day, when I try to fetch messages, I have to confirm security exceptions. The confirmations never seem to stick. This is some BS.

Recently I noticed that in ALL of my Local Folders, I can no longer see any of the content. The headers show like normal, but I cannot open / read the content (presumably contained therein).

I have tried repairing individual folders, but nothing changes.

I have tried eliminating the .msf file, but nothing changes. A new .msf file is created, but the content is still not visible.

If I try and reply to a local email, the email is empty with the exception of the subject. Even though it shows the sender of the email (i.e. From), neither the email address nor the email content is copied into the reply.

I am slowly starting to worry that the individual files storing the email content are corrupt, but if I open the content file (i.e. non-.msf file) with Word, I get what I presume is the first / oldest email, but nothing more (even though the files are many MB large).

Is it significant that I have both "Local Folders" and "Local Folders.sbd" (as folders)? The content within them appears to be similar if not identical.

My email is stored on a NAS which I can access from any computer on my network (presuming I have set up Thunderbird appropriately); can this contribute to the issue?

Any other ideas which might lead to such an annoying issue? I really don't want to have lost all my emails for the past 20+ years.

Thanks in advance for any suggestions you make.

My desktop computer died, so I needed to copy all my data files from backup (which worked fine) and then install all the apps that I regularly run on my laptop. When I installed Thunderbird, I got the latest Release 139.02. It behaves very differently from what I think is called the "Classic View" that was running on my Desktop. I REALLY hate it, but can't figure out how to set the Thunderbird parameters to do that. My problems include:

-- Overview of Thunderbird "Views". I can't find any documentation that explains [a] the various viewing options that Thunderbird offers and [b] EXACTLY how to set them.

-- Release Notes. I haven't found any release notes to explain when/why a major change to view was done.

-- Periodically, even for same release, Thunderbird CHANGES my parameter settings. Most annoying is changing the General Message-List settings to "Show Only Display Names For People in My Address Book". I live in a retirement community where many husbands & wives share the same Email address. With this setting, Thunderbird shows the name associate with the first message I received from this Email address. So the heading doesn't show which person actually sent it (although I can make a good guess when Thunderbird is telling me it came from a dead person. [g]

Is there ANY way I can get Release 139.0.2 to display messages the way I've been seeing them for at least 10 years? I REALLY need help. (If I can't get Thunderbird to behave the way I want, seem like I might as well switch to reading/writing messages directly from Google Gmail web site. It's equally lacking in documentation, but I suppose that eventually I could figure it out.)

Thanks in advance for any help anybody can offer.GMail, I'd seriously consider switch to using Gmail directly without Thunderbird.)

I was searching for an email that I had just deleted and discovered that the Trash folder connected to my inbox was empty. The one connected to my Local folders, however, was not. I cannot find a setting that would instruct Thunderbird on how long to save emails in the Trash folder and am sure I did not accidentally change anything. Any idea how to fix this?

I'm in the process of cleaning up Thunderbird e-mail before moving to a new computer. I started with 11,593 e-mails in my Inbox and 7,799 e-mails in my Sent folder. I'm now down to 7,634 in my Inbox and 4,965 in my Sent folder. I've allocated 2 weeks for this process and found that it's taking me about 3 hours per day to meet my daily goals. I'm finding that I'm spending at LEAST half the time responding to "Empty-Trash/Compact-folders" requests. There are times I can delete 50 e-mails at a time without getting a request. Other times I will try to delete ten e-mails and get the request. With the old version of Thunderbird I could literally delete hundreds of e-mails at a time. Can you help? Russ Bukwa Yardley, PA ps. I have intentionally given you specific numbers. Based on my software- and test-engineering experience, I speculate you need to create a stress test to solve this nagging problem.

Having selected multiple messages, I'm trying to move them to a new sub-folder, however this option seems to have vanished! I've installed version 139.0.2 (64-bit).

Hello,

Recently I have started to have emails fail to deliver to a certain domain and the message that comes back is

550 DKIM Sender Invalid - envelope rejected.

I am using Thunderbird v128.8.1 esr (64-bit). Extensions installed are: 1. Attachment Saver (Deimios, v.0.2.2) 2. FileLink provider for Send (Teal Dulcet v2.1.1) 3. Remove Duplicate Messages (Eyal Rozenberg v0.6.1)

I have been in communication with this client for several years and not had this problem before. When I send email to the same recipients using WebMail there is no problem, it is only when I send from Thunderbird.

I am not using any encryption type of setup.

Has anyone come across this before? Does anyone know of a solution?

Thanks, Franc.

I receive email fine. The website email works fine. I cannot send email via thunderbird and have not changed my settings which worked for years. my smtp account. I have rebooted my Windows 10 pc numerous times. What can do this? How can I fix this>

I suspect there is no fix and I (possibly) can restore from backups, but I would sure like to know what the issue is.

I tried retrieving an e-mail from the "folder" where I kept e-mails from 2023. The "index" one sees displayed for the folder had e-mails from Jan-Mar of 2023, but Thunderbird froze when I tried to open any of them. I tried the repair function (which I imagine is meant to rebuild the .msf file), but after than the index contained nothing from Jan-Mar. I opened both the .msf file and the no-extension file in Notepad, but I see nothing from those months.

Any clues/help would be appreciated.

In transitioning from a Windows 10 Laptop to a new Windows 11 laptop, Thunderbird reports that "Thunderbird profile cannot be loaded. It may be missing or inaccessible" I've copied three times an 11gb Profile from the W10 to the W11 laptop using a micro SD USB transfer, which seems to be successful, and the file names are identical. The copy is directly from the Explorer location under User, AppData, etc. and conforms to instructions from Thunderbird.

Although Thunderbird runs fine with multiple email accounts In the Windows 10 laptop, when I clear Cache and restart Thunderbird, I get a message: "file link provider for WebDAV Account not properly configured". I don't know what that means. Don't know if this is causing the Profile problem.

Please help if you can.

Thanks, Gary Rubin garyrubin00@gmail.com

An extremely irritating bug in Thunderbird. Don't even remember how long it has been doing this; when I am typing a message, if I so much as switch away from the Thunderbird window (to look something up for example), when I come back to the window it will switch the font size to 1-2 points smaller than what it had been doing before. I have not selected any formatting settings, and had been typing in it's default type size. Merely switching out of the window should not perform a type size change.

I have ever had to just highlight the entire message (if TB has completely fubarred the font), delete it from TB, paste it into a plain-text editor to remove all formatting, and then paste it back in.

My Thunderbird is IMAP'ed to my generic usa.net email server. It downloads everything to Thunderbird serving as backup only. I have set that local delete does not delete on the server.

It has now amassed ~200.000 emails in the active Thunderbird Inbox. (No, I don't want to delete any !:o) I want to move the ~200.000 emails to a local folder not affecting the ongoing download sync from usa.net. The local folder is to be offline.

How do I bulk move the ~200.000 emails in the active Thunderbird Inbox to a local Thunderbird folder? - not deleting anything locally or on the server - keeping the sync download from the usa.net server running onwards into the now purged Inbox - not having the sync re-download from the server (defeats my intended purpose #:o)

Microsoft Outlook Client emails are legally valid in a court of law, but Thunderbird emails are not. Can we start taking baby steps towards making Thunderbird emails a little more viable in legal applications?

While I do not understand these things in the depth required, can we start taking baby steps towards achieving legal validity of emails downloaded from Thunderbird?

I am presenting below a conversation that I had with chat GPT regarding this matter for the help of anyone who wishes to take this up.

Chat GPT:

QUESTION 1: 1. As per my limited knowledge, Outlook client emails are legally valid because the header cannot be edited. This however, is not true of Thunderbird emails. Do I understand correctly? 2. What are the challenges in making Thunderbird header not user editable, so that Thunderbird emails also have the same benefit?

Chat GPT: Your question touches on email authenticity and legal validity—especially in regulated or evidence-sensitive contexts. Let's break it down:

Is it true that Outlook headers are immutable and Thunderbird’s are not?

Partially True — but needs clarification.

Email headers in both Outlook and Thunderbird

Can be viewed by recipients, but cannot be edited after the email has been sent. Only during composition can certain headers (like `From`, `Reply-To`) be changed, depending on the setup.

What you cannot change post-sending:

After an email is sent (from any client), the core SMTP headers (`Date`, `From`, `Message-ID`, etc.) are locked. These are generated by the sending server and cryptographically traceable via server logs or DKIM.

Outlook’s extra layer:

Outlook integrates closely with Microsoft Exchange, which stores server-side logs, message tracking, and non-editable audit trails (e.g., via journaling). That’s what gives Outlook/Exchange emails more evidentiary credibility, not just the client itself. In contrast, Thunderbird usually connects via standard IMAP/SMTP, without server-side logging, unless used with a corporate mail server like Postfix + Dovecot + journaling.

In Summary: Table Feature Outlook (w/ Exchange) Thunderbird Headers editable during composition Yes (some fields) Yes (same) Headers editable after sending No No Built-in server-side logging Yes (Exchange) No (unless configured) Strong evidentiary trail Common in enterprise Requires external setup

What are the challenges in making Thunderbird headers non-editable during composition?

The challenge lies not in technical impossibility, but in the design philosophy of Thunderbird:

a. Open Source & User Control

Thunderbird is open source, so users can customize or even extend the client to manipulate headers (via extensions or config changes). This is powerful for advanced users, but not ideal in regulated or high-trust environments.

b. Lack of Server-Side Enforcement

Thunderbird relies on whatever SMTP/IMAP servers it connects to. Unless the server enforces policies (like DKIM signing, DMARC, or header filtering), client settings are only soft limits.

c. Missing Native Audit Features

Outlook/Exchange logs metadata like when a message was sent, delivered, read, etc. Thunderbird lacks that unless paired with enterprise-grade backends. How Could Thunderbird Improve Legal Trustworthiness?

1. Header Locking During Composition

  	Disable or grey out fields like `From`, `Date`, `Message-ID`.
  	Possible via extension, but not enforced by default.

2. Enforced Server-Side Signing (e.g., DKIM)

  	Ensure outgoing mail is cryptographically signed to verify integrity.
  	Requires a properly configured mail server, not just Thunderbird.

3. Journaling or BCC Archiving

  	Auto-BCC all sent mail to a tamper-proof archival system.
  	Thunderbird can do this via rules or server configuration.

4. Extension or Mode for “Forensic Compliance”

  	Custom Thunderbird modes that restrict editing headers, disable extensions, log actions, etc.

Final Thoughts

You're correct in understanding that Thunderbird offers less baked-in legal reliability than Outlook + Exchange. But this isn’t due to insecure design—rather, it's due to Thunderbird’s flexibility and lack of tight server integration. Thunderbird can be made trustworthy with the right server configuration (DKIM, archiving) and possibly some custom add-ons.

If you’re looking to build or propose a “forensic-grade” Thunderbird environment, I can help design one with proper technical constraints and audit trails. Let me know!

QUESTION 2: My legal Counsel has told me that emails downloaded from the Gmail server into the outlook client are legally valid. So even without Microsoft Exchange and all the other server side logging, Outlook emails are legally viable. Chat GPT

Yes — your legal counsel is broadly correct, and here’s the nuanced explanation:

Emails Downloaded via Outlook (from Gmail) Can Be Legally Valid

Even without Microsoft Exchange, emails downloaded into Outlook (say via IMAP or POP from Gmail) can still be legally viable evidence, because:

1. Outlook stores email in a tamper-evident format

Outlook saves emails in `.pst` or `.ost` files. These files have a structured, proprietary binary format that is hard to tamper with without detection. Courts often accept these files (with chain of custody) as original records.

2. Outlook preserves server headers

Even when connected to Gmail, Outlook does not modify or fake headers. It shows server-signed headers (like `Message-ID`, `Date`, etc.) exactly as received. These headers can be verified independently against:

Gmail’s “Show Original” → raw headers DKIM/DMARC authentication

3. Integrity from Gmail itself

Gmail assigns unique `Message-ID`s and signs outgoing mail with DKIM. DKIM proves the message has not been tampered with since it left Google’s servers. So even if Outlook is the client, the source of trust is Gmail + DKIM, not just the software.

In Legal Contexts

4. What courts typically require is:

 A copy of the original message as received (headers intact)
 Some form of chain of custody (who had access, how was it stored)
 Optionally, confirmation from the mail server logs (if challenged)
 Outlook is often used in corporate/legal environments because:

It does not let users easily forge full headers The data format is harder to manipulate Legal teams and forensic experts are familiar with `.pst` files

So even without Exchange, emails received and stored in Outlook are trusted, provided:

The full headers are intact The `.pst` or `.ost` file has not been tampered with

5. How This Differs from Thunderbird

Thunderbird also preserves headers and stores messages locally — but: Table: Aspect Outlook Thunderbird Storage format `.pst`/`.ost` (proprietary) `.mbox` or plain text Header immutability Enforced by format Editable via text file (with effort) Forensic familiarity High (in legal circles) Moderate Tamper-evidence Strong (binary format) Weak (editable with text editors)

So Thunderbird messages can technically be altered more easily after download, especially if stored in `.mbox` or `.eml` formats. That’s why they are viewed with more caution in legal settings.

Conclusion

Yes — emails downloaded into Outlook, even from Gmail, are generally accepted as legally valid, provided the headers are intact and the file has not been manipulated. Outlook's storage format and market reputation contribute to its legal trustworthiness — even without Exchange.

If you want to achieve similar legal credibility with Thunderbird, the focus should be on:

Enforcing DKIM-signing (from Gmail, already done) Locking down `.eml` or `.mbox` file access Possibly archiving in tamper-evident formats

Let me know if you’d like a workflow to export Thunderbird emails into a legally robust format similar to `.pst`.