Thunderbird Community Forum

I'm using Thunderbird from a little time anmd I have a problem with "Unified Folders" After installing it, I added my 10 accounts one by one and found out a problem. Simply Thunderbird doesn't want more than 1 "yahoo" account. I can enter even 15 accounts and Thunderbird can manage all the accounts with "Unified Folders" without problems and I see all the accounts. But if I were to add another "yahoo" account, Thunderbird no longer handles it with "Unified Folders". In fact it disappears and I only see it again if I activate "All Folders". I can't understand why. Maybe I need to setup something on yahoo? Can I solve this problem? Thanks PS: I speak italian.

Recently tried to switch back to using Daily, but now I get authentication errors each time I start the program. It's always the following three errors in sequence: Authentication failure while connecting to server imap.gmail.com. The certificate for imap.gmail.com does not come from a trusted source. Non-overridable TLS error occurred. Handshake error or probably the TLS version or certificate used by server imap.gmail.com is incompatible.

I've tried getting rid of all of my saved passwords and even completely getting rid of the account and re-adding it. I've also tried completely disabling my VPN's service in Windows to see if that was somehow affecting it, but nothing.

The oversized menu box cuts off the the "Save" key and I can't re-size the Message Filter/New Filter box nor can I slide it up for access to the button on the very bottom. Windows 10 Home, Version 22H2, Installed on 9/14/2021, OS Build 19045.6466.

I've tried a dozen fixes suggested by Duck AI and none had any effect on the Filter box. Here’s a concise list from Duck AI of every fix I tried:

   Hold Shift while opening the Filter menu (compact popup).
   Shorten long filter names (Tools > Message Filters).
   Change system UI scale (Windows Display scaling).
   Toggle toolbars / layout to reclaim space (View > Toolbars / Layout).
   Use Tools > Message Filters dialog (resizable) instead of the menu.
   Add userChrome.css rules (multiple variants) in profile/chrome/userChrome.css to force max-height, scrollbars, reduced font/padding:
       Generic menupopup rule (max-height: 420px, font-size: 11px).
       Targeted rule including .filter-menu-popup and #createFilterFromPopup (max-height: 300–520px, font-size: 10–11px).
       Final variant replacing values with 360px (no effect).
   Attempted diagnostics via screenshots and Developer Toolbox (Ctrl+Shift+I) — determined screenshots showed Filters dialog, not popup.
   Determined the "Create Filter From" list is likely a native Windows popup (userChrome.css cannot style).
   Workarounds proposed:
       Use the resizable Message Filters dialog to create filters manually.
       AutoHotkey script (Ctrl+Alt+F) to open New Filter and pre-fill From/To/Subject from the selected message (provided full script).

I had received several emails from an individual over the past few weeks. All emails displayed in the inbox (on my desktop computer) as they should. This afternoon suddenly all of these emails disappeared from the desktop inbox. The emails are still on the server and are and can be viewed in the inbox on my laptop but not on my desktop. If I use the quick filter function in the desktop the emails are there but not in the inbox. I assume some sort of filter accidentally was activated (I did not attempt any filter changes) but I can't find how to remove this filter function so the emails again appear in the inbox as they should. Please provide detailed instructions how to get these emails to reappear in the desktop inbox.

I have been using this system since 2008 through a company called Bluewave. They are shutting down at the end of May and I need full service for everything but main email. I need to talk (like on the phone) to someone who can help me in some way. I am not computer savvy so please have someone patient. I own AuPurr Cat care and don't want to lose our database, etc. info already on file. Am I contacting the right company for this help? My direct # is [edited phone# from community support forum]

Hello,

This would have been a reply to https://support.mozilla.org/en-US/questions/1390397?utm_source=chatgpt.com which is one of the top google results for "Thunderbird make font fixed length addon"

Some html text is hard to read, I would like a button, to make it all one more readable font. (font override toggle button to variable lenth font) and a button to make it a fixed length font (font override toggle button to fixed lenth font) Maybe a button to also strip formatting like bold/italic/coloring etc..

The solution

Preferences > General > Language & Appearance > Fonts & Colors > Default font > Advanced > Font Control > Use fixed width font for plain text

Which is too deep into the setting to casually flip for one message and then bring back to normal. I don't want this forever, just when there's one hard to read email.

I have been using this system since 2008 through a company called Bluewave. They are shutting down at the end of May and I need full service for everything but main email. I need to talk (like on the phone) to someone who can help me in some way. I am not computer savvy so please have someone patient. I own AuPurr Cat care and don't want to lose our database, etc. info already on file. Am I contacting the right company for this help? My direct # is [edited phone# from community support forum]

Hi there,

When attempting to send emails through Thunderbird, I get the following error messages:

Login to server smtp.long-mcquade.com with username X@long-mcquade.com failed.

Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) . Please check the password and verify the ‘Authentication method’ in ‘Account Settings | Outgoing server (SMTP)’.

When testing the server connection in server settings and outgoing server settings, I successfully establish a connection, yet I am still unable to send messages.

(PII redacted by moderator)

I've done it many times - copy the folder under Profiles to a big memory stick, copy that into Profiles on my other (travel) computer, and all is well. But this time, I got the "old version of T-Bird" message. Nothing I try fixes it. I made sure that both computers downloaded today's versions. It keeps giving me the "old version F you" message. Help!!!!

I am trying to reinstall Thunderbird on my computer using Windows 10 and I get a pop-up box requesting to sign in to my Google account and then an authentication error message. How do I get past this?

I have closed my Rogers account and have opened a Wightman account. Before I closed the Rogers account I downloaded Thunderbird and transferred my e mails and contacts to Thunderbird. To do that I had to put in my Rogers address. Now, when I open Thunderbird or try to send a message from Thunderbird, a pop up asks me to sign in to the old Rogers account. As this account is no longer active I cannot use Thunderbird. I have tried to change the information from Thunderbird E mail but cannot get it to change. My new e mail address is martinwea@wightman.ca Please help me to make Thunderbird work properly! Martin

My business has two domains. I can send email to a Gmail account holder using the primary domain with no issues. But amy emails from what I call the "secondary" domain below are treated as spam. This occurs with two different email addresses using the secondary domain.

Both domains are hosted with Bluehost. Exhaustive research has revealed the following:

• Settings in Thunderbird are exactly the same, e.g. ports, security, SSL/TLS, etc. for each domain.
• There is no subject line or content that could possibly be regarded as spam.
• MXToolbox indicates that the secondary domain is not on any blacklist.
• Extended support via Bluehost reveals that SPF, DKIM, and DMARC records are all correct.
• Email sent to a Gmail account using the CPanel (Roundcube) is not flagged as spam. Only emails sent via Thunderbird are flagged.
• Emails sent to a Gmail account from the secondary domain using my mobile phone, but still on the same network/IP address, are not flagged as spam.
• If I first send an email to one of the secondary domain emails FROM Gmail, then reply to it, the reply is not flagged as spam.

After many hours of head scratching (and later, head banging), I am pretty much at my wit's end with this problem. I'm an electronic engineer but this one is definitely out of my wheelhouse. Any help would most certainly be appreciated!

Thanks in advance, Don

After being migrated from f9 to Greenby my service was suspended by Greenby for several weeks. During this period I was getting requests from Thunderbird for pass word. The Greenby is now reinstated but I am still getting password requests from Thunderbird and cannot connect with my original email address.

Have TBird 102 Installed on 2 Dell LapTop Machines - Win10 OS

The Installation Process Completes but am having issues with the

Incoming Email Server Settings, and the Out Going Email Server Settings. 

On One Installation ( Nov2025 TimeFrame) , the Emails come down into the InBox But Will Not Go Out.

On the Other Installation ( May 2026 TimeFrame ) ... Cannot set up Email Account ... username/password errors.

I am currently using Thunderbird version 140.10.2 esr. (32bit) I understand that to latest version is 150. I also understand that, from version 145, Microsoft Exchange accounts are supported natively by Thunderbird.

I am using a generic desktop PC running Windows 10 Pro (22H2)

I am having difficulties with an Exchange account using the OWL add on.

I would like to upgrade my Thunderbird to the latest version and use the native support for Exchange accounts. I would also, if possible, like to upgrade to a 64bit version.

When I follow the instructions (Help/Update Thunderbird) the pop up reports that 'Thunderbird is up to date'.

I can't see a way forward at present, can someone assist please.

Hi, I've been using Thunderbird latest version for a few days. Too much I have a problem that is bothering me. I have 20 accounts and if I choose Unified Folders, on the six of Tunderbird I see only a part of the Accounts and precisely 14. To solve my problem I also used the "Unified Folder Debugging" add-on but it didn't solve the problem. Why do I have this problem? I would like to use Unified Folders but I can't do it because I don't have any Accounts. Thanks for some info.

I have 3 different hotmail accounts. And tried to set them up in a newly installed thunderbird app on windows (10,sorry not up to date). In the beginning I had 2 out of 3 working, but the last one is my business account and it didn't connect. I tried many different ways to get it working, and now only the 1st one is still connecting correctly. The second one also doesn't connect anymore and is giving me the: "The connection was refused when attempting to contact localhost." or Authentication error: Unable to log in at server. Probably wrong configuration, username or password.

I know for sure password and username are correct. I have added thunderbird to exceptions in firewall. I also tried turning the firewall off. no changes. I have no idea where it got so messy but can someone guide me in this? Most of it I do not understand so it is obvious I made mistakes.