Thunderbird Community Forum

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.

I spent hours yesterday deleting and moving to local folders over 6,000 emails. Today they are all back! They appear to be all greyed out as if I had read all of them, and the ones I moved to my local folders seem to all be there in the folders I moved them to, in addition to still being in my inbox. Any help or suggestions would be greatly appreciated.

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.

I have been using Mozilla Thunderbird for decades and they have even contributed a small amount of money to Thunderbird periodically. Just within the last two or three days all of a sudden I have been unable to send emails with my phone. I receive emails, but I do not send them. So I opened up a laptop where I did not have Thunderbird and set it up properly through Spectrum using the incoming and outgoing servers as mail.twc.com. and yes, just like on my phone. I continue to receive new emails, but even with the laptop I was unable to send an email. I received the message"send message error sending a message failed. The message could not be sent because the connection to outgoing server smtp mail.twc.com was lost in the middle of the transaction. Try again."I contacted Spectrum twice and both times they had me try to send a message through their Web server spectrum.net and that message did go through. Of course then their response is that this has to be a problem with the third-party app meaning Mozilla Thunderbird, and they can’t help with that at all. I sure would appreciate some help because I hate to walk away from Thunderbird as well as change my email address after all of these decades.

ho appena inviato un post, replica ad una vostra risposta... purtroppo ho concluso con il button "solved the problem" ... per favore, ho giusto ri-raccontato il guaio, non è per nulla solved... non mollatemi, grazie. Giorgio Chiantore, 10015 Ivrea.

My Outlook account moves what it thinks are spam/marketing messages into a "Junk" folder. Sometimes there are important messages here that I must mark as "Not Junk" so that I can continue to receive new messages from this sender in my InBox. I cannot map this Junk folder into Thunderbird even after I go through the steps and checkbox this folder to be synchronized. It does not appear in the left-side "All Folders" section.

Many solutions suggest that I make changes in "Settings\Privacy & Security\Junk" section. This does not exist. There, however, is a "Spam" section. Is this the same functionality?

Further, under "Accounts\Spam Settings\" there is a "Destination and Retention" section. There is no "Junk" folder available under "Other".

Does anyone else have problems linking server-side Junk folders into Thunderbird?

Thank you in advance for taking the time if you replied, Tim

ps. I've googled this extensively, and all the presented "solutions" are not accurate as the Thunderbird "junk" options they refer no longer exist. Has there been recent UX changes, and this is now a lingering bug?