Thunderbird Community Forum

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 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 As this account is no longer active I cannot use Thunderbird.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

Hi there,

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

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

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.

Couple months back had to restore computer. Wouldn't let me add my POP gmail account, said had to use IMAP. POP was no longer accepted or something to that effect. So I got IMAP set up. (Of course, I did save my old POP folder with some messages in it.) Ever since setting up the IMAP folder I only get maybe 30 messages each morning. Never more. Which is no way right. I've googled and tweeked the synchronization/storage settings and the server settings. Nothing works. I'll spend hours googling suggestions and trying them, then get frustrated and move on. Then a week or so later I go thru it all again. Nothing changes!! Still only get the very few emails each morning. About 30 or so minutes after the initial download of messages, I'll get a pop up saying imap connection lost. This is SO frustrating. I have no idea what to try next. I never had this kind of issue with any of my POP accounts. Any suggestions? I've probably already tried them but will certainly give it another try. Thanks! Lynn

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.

After updating Thunderbird to version 150.0.2, I can no longer connect to my lolipop.jp mail servers.

Symptoms:

• Both IMAP and SMTP stopped working at the same time
• Webmail works normally
• Multiple mail accounts are affected
• Thunderbird times out when connecting to the servers
• The issue started immediately after updating to Thunderbird 150.0.2

Settings tested:

• IMAP: imap.lolipop.jp / Port 993 / SSL-TLS / Normal password
• SMTP: smtp.lolipop.jp / Port 465 SSL-TLS and Port 587 STARTTLS
• Tried Thunderbird Safe Mode
• Tried reinstalling Thunderbird
• Tried disabling Norton security/firewall temporarily
• Same issue persists

Could this be a known issue with Thunderbird 150.0.2? If so, is there any workaround or planned fix?

Thank you.

I have been using T-bird for years successfully until lately. We have multiple email addresses in Comcast and Gmail, but lately our passwords that we have been using and know are correct because they are written on paper and Keypass, are being changed somehow so that they will no longer work. When we look at the saved passwords in Thunderbird we see some have been changed on a certain date that we did not do, and the password listed now must be about 200 characters long. Then when we go to change the password, it may be listed as changed. Then when we try to send a message with that email address, we get an error message saying, for example, smtp.googlemail.com and a wrong username/address completely. I can find no way to correct the username email in any settings in Thunderbird. I have searched the Thunderbird HELP files many times, but am unable to find any of this addressed anywhere. After trying to fix these problems for most of 3 days now, I have get rid of Thunderbird for an email client that works correctly!!!

Clearly, this is a very basic question which has undoubtedly been answered before, but I haven't been able to find it. If Thunderbird had an old-style Help feature with an index, I could probably look it right up. But coming to the forum is the only option the program gives me.

Hello,

Despite the fact that I have set Thunderbird to display messages as plain text, my needs are not being fully respected. If the message contains some form of markup, presumably HTML, the font size is not what I have chosen. Generally, the font size is smaller than what I have specified in the Thunderbird settings.

This is unacceptable. It is a usability / accessibility issue. If the user chooses Plain Text and sets a font size, they have done that for a reason. Which is accessibility. If Thunderbird ignores the needs of users and applies styling rules to messages, that is a failure state.

Is there some way to actually, truly, absolutely display all messages as plain text in a specified font, weight, and size? If not, what is the protocol for reaching developers so that they can respond to this issue?

Thank you

With 03.04.2026 they began to notice that the attached emails in eml format (the attached emails have attached documents, mostly pdf) sent from yandex mail stopped opening. Everything used to open well. Eml also does not save to disk. If you send the same files via Gmail, everything opens. Program version 150.0.1

Hello,

I am on Thunderbird 150.0.2 for Windows.

I am really suffering here. I need to change the font weight of unread messages. In a non-threaded list.

The default weight I get with my preferred font (Trebuchet MS) is not bold. It is BLACK. When I say BLACK, I mean ultra bold, display font, heading weight. Heavier than the boldest font that even exists in the font family. Thunderbird is creating this ultra mega black font by taking the bold font variant and applying a faux bold effect to it. The result is that the text is so heavy that it takes up twice as much horizontal space as the ordinary bold font variant. This becomes a usability issue because it's not possible to see the date, sender, and subject at the same time.

I have struggled and strived with userchrome.css. Spent hours combing through forums here and elsewhere. I've already enabled the mystery setting in the config editor. I put userchrome.css where it is supposed to be.

I saw a blog post from Mozilla that says "userchrome.css is not supported". What is the actual meaning of this? That it has been actively blocked from working anymore, ever, for anyone? Or that users are taking risks if they create userchrome.css? Why can't developers speak plain language? "Not supported" could mean many things.

When I go to the Style Editor, userchrome.css does not exist there. Which leads me to believe that user customizations are absolutely deprecated and we are not permitted to use userchrome.css.

I tried editing some of the rules in the Style Editor, but could not determine any way of actually storing the changes. When I click Save, I get a dialog where I can **EXPORT** the file. But I can't seem to actually save the changes, because CSS files do not appear to exist in the installation directory. It must be compiled into some library.

This is extremely unsatisfying and super frustrating. Just getting straight answers to things is super difficult, nothing stays the same for more than a couple months, and up to date information either does not exist or is not found by any search engine.

So, please help. I just need to change one setting, the font weight of unread messages. Since Thunderbird is allegedly open source, I thought I would have some ability to make such changes. But the Style Editor doesn't seem to actually be an editor, but merely a read-only interface to precompiled rules? If I wanted to change the font weight of unread messages, would I be forced to compile my own version of Thunderbird? I'm not competent to do that, and it would probably either prevent updates, or the updates would break my changes.

Please help, I am super desperate. I need to see the date, sender, and subject all at the same time. That doesn't seem like an unreasonable ask.

I would gladly pay for an email client that gives me control over my data *and* allows me to control the UI, but apparently that doesn't exist.

Ever since the latest update, when I hit send for an email. It says it cannot send, I cancel, hit send again and it goes through. I have to try sending EVERY email twice.

I just installed a new router and all of a sudden nothing is working properly on my PC. Among other things, I need to fix Thunderbird, and for that I need to find where my thunderbird profile is. The instructions I've seen say to go to troubleshooting information, find profile folder, and click on "open folder." When I do that, nothing happens. (I told you installing the router appears to have broken everything--I don't know how that happened, especially since I was on the phone with tech support for the router for install), and I'm no closer to finding the profile file. I can enter %appdata%\roaming\thunderbird\profiles but that shows me two different profile directories and I don't know which one is the right one. How can I find the correct file and why doesn't troubleshooting information just show me that?