Thunderbird Community Forum

Preamble:

1. There are 34 email Accounts listed in left column.
2. (Image 1) When in "Mail" column I can see down to only the Account Name (address). There is only the Account Name and Inbox.. nothing else below that can be seen - no Drafts, Sent, Archives, Spam, or Deleted. Anything below is missing too.
3. When choosing "Account Setting", everything for last account shows up, plus Outgoing, Add-ons (Image 2). Too, we can see the Offline/Online Icon.

QUESTION: How may I fix it so that the last account shows all sub-sections of the account - i.e., Server Settings, Copies & Folders etcetera right on down to Online/Offline or at best, down to "Return Receipts" for the last account?

Thanks for volunteering, ~r

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.

Hello, can someone please fix this e-mail address please & thank you.

Following the instructions provided at this web page: https://developer.mozilla.org/en-US/docs/MDN/Community/Community_Participation_Guidelines I e-mailed a code of conduct violation report to the provided email address, mdn-cpg-report@mozilla.com

Actual results:

I immediately received the following e-mail reply, telling me in effect that my e-mail could not be delivered:

Subject: Delivery Status Notification (Failure) Date: Sun, 15 Feb 2026 21:34:30 -0800 (PST) From: Mail Delivery Subsystem <mailer-daemon@googlemail.com> To: [redacted]

Hello [redacted],

We're writing to let you know that the group you tried to contact (mdn-cpg-report) may not exist, or you may not have permission to post messages to the group. A few more details on why you weren't able to post:

You might have spelled or formatted the group name incorrectly. The owner of the group may have removed this group. You may need to join the group before receiving permission to post. This group may not be open to posting. If you have questions related to this or any other Google Group, visit the Help Center at https://support.google.com/a/mozilla.com/bin/topic.py?topic=25838.

Thanks,

mozilla.com admins

[headers, etc redacted]

Expected results:

I expected instead to receive a reply telling me that my e-mail had been successfully received.

None of the topics suggested fit. I'm having trouble with getting extensions on toolbars. In the customize toolbars window there's a toolbar at the very top of the page that starts with mail, calendar, addressbook, etc. Just for example, the Google Calendar and Outlook Calendar extensions are in that toolbar, but I can't move them to another toolbar and that toolbar disappears when I close the Customize page (either way) and I haven't been able to find a way to get it displayed in other places. That toolbar is very similar to the toolbar that appears on the left side of the Thunderbird window, but that one doesn't include the extra extension buttons that I mentioned above.

Some people in various places have suggested that customizing Thunderbird toolbars is done the same way as in Firefox. But I haven't been able to find a puzzle piece icon anywhere.

By the way, I used to be able to add more toolbars, which I found to be an attractive concept, although that implementation didn't always work so well.