Thunderbird Community Forum

Dear Thunderbird Developers,

I am writing to express my frustration regarding the recent UI changes. After the latest update, the standard toolbar icons (Get Messages, Write, Address Book, reply, etc.) completely disappeared for me, leaving behind nothing but a search bar. Even using the "Restore Default Set" option fails to bring the essential navigation buttons back. While I can eventually fix these issues as a power user, these constant, breaking UI changes are a major problem for average users. For instance, my 65-year-old mother relies on a stable interface. Every time a rollout breaks the visual layout or hides basic functions, she is unable to use her email until I step in to fix what the update messed up.

Forcing users to manually rebuild their primary navigation toolbar after an update is not a "feature"—it’s a regression that alienates long-time especially elderly users who need reliability over constant redesigns. Please prioritize UI stability and ensure that "Reset to Default" actually restores a functional set of icons.

If you need further information I'll be glad to hear and hope you can give me an easy fix for this problem.

Please answer andere the following address: [edited email from community support forum] Or send a notification with a link to this thread

Best regards,

Dilan Adler

Windows 11 machine. I have 2 email addresses in my TB set-up, from different domains/servers, one is a Rackspace for my business and the other is Fastmail. I am repeatedly asked for the server password for every single incoming email, and occasionally asked for the SMTP outgoing password when sending. I have put Windows into safe mode and it still happens there. I just don't know what to try next. Thanks in advance, Laurel

For many years I have had a Thunderbird Calendar, and have a large number of Tasks set up in it. I have now decided it would be convenient to link it to my Google calendar, so that it also shows on my new Windows 11 machine and on my laptop. I've gone through the process described in the "Create new calendars" article, to link the calendars, and the Google calendar is now appearing in the Thunderbird calendar, but not vice versa. How do I get the Tasks in the Thunderbird calendar to appear in the Google calendar?

I am running Thunderbird 140.7.1esr and Firefox 147.03 on my Windows 10 machine, which I used to set up the link. My Windows 11 machine has the same Firefox build, but Thunderbird 147.0.1, and the Google calendar display is the same, but I haven't yet set up the Thunderbird calendar on the new machine.

Dear Sir / Madam, I am still running a perfectly good Win 7 computer. My Mail Inbox & Sent Box have a huge number of Emails i have been trying to delete in batches. They initially go to my Deleted folder which shows the number of emails collected. I then empty the deleted folder. so far so good, except the huge file size in my inbox or sent box hasn’t changed! But the deleted folder is now showing empty! The emails i selected to delete seem to have disappeared, but i have not recovered any disk space! I am running out of disk space in C drive because i cannot seem to remove these emails. I have tried shutting down my computer & rebooting (i shut it down every night) this has no effect.

If i had a tool to open the sent / inbox file i could manually delete emails in old date order? Hope someone out there can help.

Kind regards Nick

bob.fannon

Feb 14, 2026, 13:01 CST

I have used Thunderbird for a number of years with Plusnet (using POP settings) in the UK. However, Plusnet has transferred their support to a company called Greenby who have made a hash of it and offer very poor support. So, I want to use Outlook as the mail server but I am unable to send any messages via Thunderbird to the Outlook server. I can however download messages with no problems. The error message I get is :- Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) smtp.office365.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'

My default Outgoing Sever settings are :- Server Name : smtp.office365.com Port: 587 User Name: bob.fannon@outlook.com Authentication method: OAuth2 Connection Security: STARTTLS

I have tried deleting the Thunderbird account and re-creating it but still got the same result. I also tried to use my old Icloud account ( having first setup my App Specific password) but got the same result.

Windows 11 been working ok for years........incoming emails ok. Now emails outgoing.. not working since last update. Can Type a message and hit Send.........but its not received or opened at the other end. Is there a configuration or filter problem cutting in ??( keep it simple..old guy 80 yrs .).barry

Hi there,

I currently have three email accounts set up in my Thunderbird client. I’d like to disable the automatic marking of messages as read—but only for one specific account (mainly for my colleagues’ convenience, as it’s a shared inbox).

In Settings > General, I see the option to turn off "Automatically mark messages as read", but this would apply to all my accounts, which isn’t what I want. I’ve checked the Account Settings for the relevant account and couldn’t find a per-account option. I also looked for an add-on that might help, but so far, no luck.

Has anyone found a workaround or solution for this? Any advice would be greatly appreciated !

Thanks in advance, Cheers.

Thank you for your message. In my online account (IMAP), the "missing" folder is still there as usual. However, right-clicking it doesn't lead to the "Subscribe" option.

The folder is present in Outlook Web, but not in Thunderbird. Perhaps a checkbox is simply missing in Thunderbird.

Dear Support Team,

I am experiencing problems logging in to my Onet email account. The issue occurs when I try to access my mailbox, particularly through Mozilla Thunderbird.

Could you please let me know what might be causing this issue? Is there any specific configuration required in my Onet account settings before logging in?

Additionally, do I need to reconfigure any settings in Thunderbird (such as incoming/outgoing server settings, ports, SSL/TLS, or authentication method) to ensure successful login?

I would also like to mention that I do not experience any login issues when using email accounts from Wirtualna Polska (WP/O2) or Gmail in Thunderbird. The problem seems to occur only with my Onet account.

Please let me know if you need any additional details from my side. I would appreciate your guidance on how to resolve this issue as soon as possible.

Kind regards, Konrad

I created a new address group, and it was created under Collected Addresses. I want to move it to another one of my address books. I tried drag and drop with no success, and there is no copy/paste option.

I recently lost incoming emails to my inbox. I am in the process of setting up a website and had to change the DNS settings to proceed with the website. Since then I have lost incoming emails to my Firefox email. Which also references the domain name. I'm not technical at all so I'm wondering what I need to try to get back to access. I'm wondering if it's something to do with the outgoing server settings ? Any help much appreciated, thanks.

I have a backup file from another thunderbird installation. The profile in this backup contains a file named abook.mab. I suppose this is the address book. I would like to copy the addresses from this installation to my current thunderbird 147.0.1 (64-bit). Tools > import > address book does not work. Can you please advise me?

I am unable to send an email from Thunderbird to 2 hotmail accounts that I have been communicating with for several years. The issue has only recently started and I can send emails to them from another email account that I have on gmail and any other emails than these are fine from Thuderbird Below is the return message that I receive - can you help

   ""  This is an automatically generated Delivery Status Notification.      

Delivery to the following recipients failed permanently:

  * andyfmorris@hotmail.com

Reason: A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server ?? responded with: ** andyfmorris@hotmail.com ??:?? This message was created automatically by mail delivery software on the server .

Reporting-MTA: dns; avasout-peh-004 [212.159.14.20] Received-From-MTA: dns; [192.168.1.81] [51.7.113.34] Arrival-Date: Tue, 17 Feb 2026 11:05:53 +0000

Final-recipient: rfc822; andyfmorris@hotmail.com Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [212.159.14.20] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [Name=Protocol Filter Agent][AGT=PFA][MxId=11BCD72C9602F57A] [DU2PEPF00028D0F.eurprd03.prod.outlook.com 2026-02-17T11:05:53.185Z 08DE6B964EE3CE26]

Last-attempt-Date: Tue, 17 Feb 2026 11:05:53 +0000 ""

Hi!

I've added some subfolders to my inbox on my laptop but these folders dont appear or sync on my phone, I've checked all settings and they seem to be in order. Can you point me in the right direction to fix this?

Cheers,

Henk

After an email update this morning, I went in to look at an old email and nothing was there. Checked all my other folders and they were all empty. How and/or can I get them back. Some were ones that I did not need to loose.