Thunderbird Community Forum

I have 2 parallel accounts with the same ISP. As of 2 days ago, whenever I try to send mail, I get this message: “Sending of the message failed. An error occurred while sending mail. The mail server responded: Command rejected. Please verify that your email address is correct in your account settings and try again.” I receive mail as normal. Using the other address with exactly the same settings allows me to send normally as I have for the past ten years! Nothing appears different anywhere in the settings. There were no upgrades that I am aware of. I have since found that I can send from my basic little "travel" computer without issue. Any ideas? BTW, using POP mail settings.

Bonjour je n'ai plus accès à Thunderbird. Un bug de l'éducation nationale m'a fichu mon compte thunderbird en l'air. Je ne trouve plus mon mot de passe... du coup je ne peux plus l'ouvrir. Je n'ai désinstallé et installé de nouveau mais toujours le même problème. Je suis sur mac... Merci d'avance Murielle

Jeg har modtaget en mail som jeg vil videresende til en anden person. De modtagene mail ser sådan ud se billede Skærmbillede 2026-01-28 152737.jpg Når jeg sende denne besked videre kommer der først en lang teknisk liste, se skærmbillede Skærmbillede 2026-01-28 153123.jpg

Hvordan undgår jeg at få al den unødvendig information ?

Med venlig hilsen Michail Grunnet mobil [edited phone# from public community support forum]

I am trying to create filters for all the spam I have been receiving. It mentioned a tools menu for adding additional filters, but I am not seeing a tools menu anywhere,

When downloading a ICS appointment file to thunderbird calendar it takes you through 3-4 step for one download. Is there a shorter way to download ICS files to thunderbird calendar?'

Continuation of my prior post: https://support.mozilla.org/en-US/questions/1516342

Thunderbird has a routine problem with being unable to log into various mail servers. I have four accounts and they all seem to share this problem.

Most recent update: I've tested this in Windows Safe Mode, and the problem has not appeared. Since I can't do any useful work in Safe Mode, it's hard to give it a thorough test, but so far so good. Also, I have removed AVG antivirus because it was redundant. I have seen no improvement since it was removed.

Can this problem be resolved?

Greetings: Running TBird desktop with email provider Fidei. The email portion works fine (can send & rcv emails)...but upon accessing any of the other features, like Calendars or Lists...the content appears for a moment, then the Login dialog pops & my content for that feature goes blank. I'm providing (what I believe are the correct credentials) but it appears not to accept them...popping again. Are there separate credentials I should be providing for the other features of TBird? It didn't used to behave this way. Thanks in advance for any feedback/guidance. Ed in Tampa

Using FireFox browser

If IMAP folders have been deleted from the server, my understanding of the expected result is that they would no longer be visible on the client. Instead they display in an italic font. Is there a way to make these ghost folders go away? I've tried Unsubscribe from Deleted Folders (Folders display but no tick box to unsubscribe) Deleting cache directories etc all to no avail.

Am I missing something here?

140.7.0esr (64-bit)

I have Thunderbird 145.xx and I HATE message threading (conversation view). I have set 'mailnews.default_view_flags' = 0 but it is not stopping new mail from coming in and being displayed in conversation view. (UGH!!!!)

Is there a way to permanently disable this annoying feature?

I have the thunderbird app on my Linux SSD I set up Thunderbird all went fine when I installed my outlook account, I also have windows 11 so I booted into windows installed Thunderbird there and when I add the same account that i used on the linux. For some reason it wont let me sign in it gives me an account credentails error then send me to microsoft to sign in another way, the recovery email address is not the same as the one I have signed into linux on. I checked the password and recovery email I created and Im able to sign in the password is fine and the recovery email is as well. The thunderbird I installed on windows the account I am trying to add the recovery email is someone elses account not mine for recovery and its saying the password is wrong. I have outlook on my windows desktop and can sign in to that account I even signed out and back in again perfect. I checked the recovery email and password on microsoft web site for outlook and my account credentails are fine. I cant figure this out. It works fine on linux and the shortcut I have on my windows for outlook. But wont allow me to set it up on Thunderbird I installed on my windows. Why is it that thunderbird worked fine setting up on linux with my account but not on windows... I did delete microsoft edge a week or so ago I was wondering if that could be why I dont know.

Can I get an app or add on to my thunderbird email that tells me the email I have sent has been received and opened. An app or add on that does not require the person receiving the email to manually acknowledge the email has been received and read.

In other words when the email is received and opened I get a notification automatically.

PLEASE SOMEONE HELP ME

I'm having problems getting my signature to appear in Thunderbird as it does in my soon-to-be former email client. I've attached pics of the signature as it should appear and as it appears when imported to Thunderbird. I can edit the HTML code, but I'm not sure how to correct things like the image not importing when the link is correct and how to get rid of the dotted line border that shows up in Thunderbird when it does not appear in my current email client signature. I attempted to attach my HTML file, but cannot. I can post the code, if that would be beneficial. HELP!

Hi. I'm using Thunderbird for my POP account and it has stopped sending messages. It just says, Sending of the message failed. Peer's certificate has expired. The configuration related to (my server name) must be corrected. What am I to do?

I've looked at various other forums and chats, and it looks like this isn't possible...but is there a way to have T'bird expand all email threads by default for all folders, so I don't keep on having to hit the "*" to make it happen? This seems like an easy fix, whereby the user could have threads collapsed or expanded by default.

I'm trying to set up my thunderbird client (Version 147.0) to work with my Google Workspace. I understand that I should choose OAuth as the login method. The problem is that the option is not available when I try to create the account. There are only "normal password", "Encrypted password", "Kerberos/GSSAIP", "NTML" and "TLS certificate". What am I doing wrong?

Today - 26/01/2026 - Thunderbird keeps crashing for no reason. I receive a dialogue box to either quit or start Thunderbird again and to add to a crash report. I have been doing this all morning - no response. I have gone onto Mozilla Google search to see if there is a problem - nothing. I have shut down and re-started the computer - nothing happens. Please can you respond and maybe give me a customer service 'live' person who can talk me through this. I have used Thunderbird for over 15 years, but this is defeating me. I am in my late 70's and cannot cope with the way your Community site works. Thank you for your help. Hope to hear from you soonest.

For quite a few months now, Thunderbird has been acting weird. My emails download, I can sometimes open and delete some, but after a short time, it gets stuck on one email and won't open any more at all. I also can't open any menus, but I can change inbox folders, but still only the original email is shown. It's really hard to troubleshoot and try to fix, as I can't get to any of the menus most of the time. This happens in safe mode as well. This is getting really irritating as I've been using Thunderbird for many years, and I'd like to fix it rather than find a new email program.