Thunderbird Community Forum

My Windows 11 was recently reinstalled to factory settings, which uninstalled Thunderbird but saved my mobx files. I used Thunderbird exclusively to view older emails that are stored on my PC as mobx files. I do not use Thunderbird as an active email client. I reinstalled Thunderbird, but have been unable to get it to find my mobx files that are stored together in a folder.

All of a sudden my emails are permanently staying in bold in my folders, in Settings >Reading & Display Ive tried changing the 'Automatically mark messages as read radio buttons and quit etc and the same issue is happening, please advise

Quick Filter does not return correct results in Unified Inbox (Thunderbird 140.12.0 ESR)

I'm using Thunderbird **140.12.0 ESR (aarch64)** and believe I've found an issue with the Quick Filter when searching the **Unified Inbox**.

• • Steps to reproduce:**

1. Open the **Unified Inbox**. 2. Open the Quick Filter bar. 3. Enter a search term (e.g. "maddy").

• • Observed behaviour in the Unified Inbox:**

• With no "Filter messages by" options selected, entering a search term does not filter the message list.
• Selecting **Sender**, **Recipients** and **Subject** still does not return the expected email.
• Selecting **Body** changes the results after a delay, but the expected email is still **not** returned.

If I open the **actual Inbox** containing that same email and repeat the search:

• The expected email is found using **Sender**, **Recipients** and **Subject**.
• When **Body** is selected, the search takes longer and eventually returns additional matching messages, including the expected email.

This behaviour is reproducible with multiple search terms and suggests that the Quick Filter does not search the **Unified Inbox (virtual folder)** correctly, even though the same search works in the underlying physical folder.

Could you please confirm whether this is a known issue or a bug?

Hi everyone!

I'm trying to log into my email account on the domain example.com via SMTP. The email account is with yandex.ru. When I try to authenticate, it says the SMTP password is incorrect. I decided to try through Outlook, and it worked. What could be the issue?

Despite my marking messages several times as NOT spam, Thunderbird keeps on and on RE-marking them as spam. And the mails are coming from one of my own addresses, and they ARE in my address book!!!!!

There seems no way that I can stop the beast from misbehaving.

Hello, I can't receive any of my e-mails. I can send e-mails out now. Plus I can put in my password to log into my e-mail. This has been a headache for me, I have been with Thunder Bird for years.

I also get a boxes that says : Unable to write the email to the mailbox. It says to make sure the file system allows me to write privileges, and I have enough disk space to copy the mailbox. I have enough space on my computer system and all. Another box that says my e-mail is being processed. Please wait until processing is complete to get messages. I did e-mail you yesterday on these issues. As I said I can e-mail messages out now also log into my e-mail with my password. Thanks, Chris

I have two domain accounts; crumpcorp.com and dannycrump.com with GoDaddy. I have two E-mail accounts; [redacted] @crumpcorp.com and [redacted] @dannycrump.com. I use Thunderbird desktop Email. Thunderbird has the ability of use filters to perform automatic actions on messages received. One of the filters is “Forward Message To”. Unfortunately, attempting to forward messages fails. Thunderbird displays the following message:

Sending of the message failed. An error occurred while sending mail. The mail server responded: Request failed; Mailbox unavailable. Please verify that your email address is correct in your account settings and try again.

Please help with this issue.

Please respond to [redacted from community support forum] @dannycrump.com

Hello,

Tbird 153.0 (64-bit) on Windows using the Owl extension for microsoft authentication.

Everything was working fine till about 1 week ago. Apparently Cisco changed something and now I'm getting a TBird browser prompt that our Multi-factor authentication(MFA) DUO needs 'local access'. This is coming up in the 'captive browser' (I believe that is the terminology). This is the message:

Duo Desktop needs permission to access your local network.

Duo uses local network access to communicate with Duo Desktop. When prompted by your browser, please allow this permission.

I never really get a prompt to respond to this in Firefox or any other browser.

If I continue I'm dead in my tracks with this (also in the internal captive browser):

Allow local network access

Duo uses local network access to communicate with Duo Desktop

   Click the site information icon left of the web address in your browser.
   Click the toggle next to Local network access to allow access.
   The page should refresh automatically and allow you to continue.

This link is provided which isn't really helping:

https://help.duo.com/s/article/9470

Does this sound familiar? Can TBird use firefox instead of it's captive browser or allow the captive browser local access?

Thanks in advance!

Ed Mazurek Cisco Systems

After updating to 153.0.1esr(aarch64). the SEND button has disappeared. There's no way to send an email. (I can receive emails.) I am a Mac mini M2 Pro. OS 26.4.1

I cannot find a link to download a previous release of Thuderbird, which was working fine until this update.

Most of my buttons have disappeared except the send button, which doesn't work. Online help is confusing or doesn't fix the problem. I'm ready to move to a different platform. Why is this so difficult?

I tried the Toolbar fixes in this forum and got the menu to show up, thank you. (Any menu in Compose mode had disappeared. Actually, both Firefox and Thunderbird icons on desktop and Taskbar had disappeared as well, and I had to reinstate shortcuts. This may or may not be pertinent.)

But when I try to add "Send" to the menu, using customize, the "Send" icon is nowhere to be found as an option, so I cannot add it to the Toolbar in Composition mode. "Send" is grayed out in all bold textmenus. If I use Ctrl-Enter, message does get sent. Using Windows 10, still. Perhaps this is an upgrade issue?

I have this issue with my reminders for peoples' birthdays. I have an event on their birthday that comes from my Google contacts. That event has a reminder 1 week in advance. When the 1-week mark hits, I get an undismissable notification from Thunderbird. I can close the reminder window, but it'll show back up within a minute or two. I've tried removing and re-adding this calendar but it doesn't matter. When I look at the details for the event, I see that the Organizer field is Unknown Organizer <unknownorganizer@calendar.google.com>. My regular email address is listed as an attendee. This has been happening for at least the last several months, perhaps more than a year.

Why is Thunderbird consatntly coming up with "Authentification failure while trying to connect to server outlook.office365.com"? It never used to and would download my hotmail emails perfectly until about a month ago. This is very frustrating, I have removed my hotmail account from thunderbird and re installed it, works for ocassionally the back to same old message authentification failure. What is going on with thunderbird?153.02

My account setting correctly are set to store send mail in send of the account. Now: - Shoud be: a send mail goes always there - Is A send mail goes sometimes to the local send folder

Pleas, tel me how to corect that.

Kind Regards, Ruud

I had this issue some while back, then an update resolved it. Seems another update has brought it back.

Having just updated, still on ESR, I find that I now have 2 folders named "Spam", but in fact looking at the folder properties 1 is actually still "Junk".

The images explain it well.

As in the past, I'm unable to correctly rename the second Spam folder back to Junk.

It has to be the update that caused it (as previously).

When can I expect another update to resolve it?

Subject: Persistent Column and Folder Layout Issues — Not Being Saved Between Sessions

This is a follow-up to my previous support requests regarding two ongoing problems that significantly impact daily usability.

Column Settings I manage multiple accounts, and my preferred column layout is: Starred, Read Status, Attachment, Subject, From, and Date/Time. I do not use Threads, Correspondents, or Spam Status columns. Despite setting these preferences repeatedly, Thunderbird fails to retain them. Every day I must spend time reconfiguring columns across some or all of my accounts — the state varies unpredictably from one session to the next. This is a persistent, daily frustration that costs meaningful time. Most other major email clients save and reliably maintain column preferences. I'd expect Thunderbird to do the same.

Folder Panel Layout Two problems occur regularly when Thunderbird loads:

Folder order — Standard system folders (Inbox, Sent, Drafts, All Mail, Trash, Spam) should appear at the top of each account. Instead, Sent, All Mail, Trash, and/or Spam are frequently scattered among custom folders, with no apparent consistency.

Folder expansion — Most or all folders load in an expanded state, exposing every nested sub-folder regardless of whether they contain unread mail. This creates unnecessary visual clutter and requires manual collapsing each session.

Again, this behavior is uncommon in other widely-used email clients. Summary These are not one-time glitches — they recur daily and represent a significant usability gap. I'd appreciate confirmation that these are known issues being tracked, or guidance on a reliable fix. Reformatting the interface every morning is not a reasonable expectation for users.

On Saturday morning 27 June 2026 I tried to login my Orcon email account via Thunderbird (which I have been using for a long time). But my login didn't work, I got a message saying "login to POP3.orcon.net.nz with username habitation failed." On 30th June 2026 I reported the problem to Orcon.

Orcon gave me the following settings for Thunderbird. I have done that and even made a new account: Incoming Server Type: IMAP Mail Server: imap.orcon.net.nz Port: 143 SSL: Off Authentication: On (username and password required)

Outgoing SMTP Server: Mail Server: smtp.orcon.net.nz Port: 25 SSL: Off Authentication: Off

Since then I have spent many hours and going around in circles with Orcon's Technical Support to resolve this, but no luck. They blame Thunderbird. I used Thunderbird Troubleshoot Mode. The message that comes up reads: login to server mail orcon.net.nz with username habitation failed. Please can you check that your server settings above are correct? And if there is a bug? Irma