Thunderbird Community Forum

Hello, We are writing to report a technical issue on behalf of the State Educational and Methodological Institution "Educational and Methodological Office of Bobruysk" (email: [redacted from public] @uobobr.gov.by). An interface failure occurred in the Mozilla Thunderbird program starting on October 9, 2026. Specifically, the "Attach" (Вложить) button has stopped working and does not respond when clicked. Could you please help us resolve this issue or provide guidance on how to fix this interface glitch? Thank you for your assistance. Best regards, The Team of the Educational and Methodological Office of Bobruysk

Using Thunderbird 115.18.0esr Supernova 64-bit on Mac laptop OS 10.13.6. Worked fine for years, with ongoing Thunderbird updates, even though Mac OS is 32-bit. Suddenly, after 10/6/26 can't retrieve emails although I can see them on the ATT Yahoo server website. Can still send emails with Thunderbird. Inbound server settings are: POP server inbound.att.net, Port 995, SSL/TLS, Normal Password (I long ago created a Secure Mail Key, and even tried creating a new one). But inbound server name doesn't show in Saved Passwords (only outbound server with Secure Mail Key as password)? I have tried everything suggested, repaired my inbox folder, updated Thunderbird files, etc. in Profile as recommended. But still no prompt for password when attempting to get messages. Just shows "Done" at bottom left with no new messages received. But new messages are seen on server website. So it appears that Thunderbird isn't able to connect to the ATT Yahoo server to get emails. Why? And what else can I do? I love Thunderbird and want to continue using it.

Ihave installed and configured Google-4-TBSync addon to synchronise contacts between Google and Thunderbird and all works fine.

Just got an email from Google entitled "[Action Required] Mark AI agent OAuth clients as agentic for Google Workspace MCP by Nov 11, 2026"

Does anyone know if that is sometyhing I need to do for the addon to carry on working?

Thanks

I keep getting a message that says that the connection has timed out. Not sure why that's happening, but it's annoying. I have researched it some here, and changed a setting that is supposed affect that, and changed it to 2000, but it's still happening. What can I try next? Thanks

Thunderbird will not let me move messages to the trash folder. If I do move a message to the trash bin the message will re-appear in the in-box. I have tried to follow the steps in the Mozilla support website but that did not work. When I try to delete a message I get the following:

The current operation on "inbox" did not succeed. The mail server for account rex@rexperry.com responded: [TRYCREATE] Mailbox doesn't exist: INBOX/ Trash (0.001+0.000 secs).

I am using an HP desktop machine running W11. This problem did not happen until I switched to the W11 machine.

Any suggestions? Thanks, Rex Perry rex@rexperry.com

Dear Thunderbird Support Team,

We are experiencing a problem with the attachment feature in Thunderbird following a recent system update on our computer.

Since the update, the Attach option in emails no longer works, preventing us from attaching files to our outgoing messages. We use this feature very frequently in our daily work, as we regularly send documents by email, so this issue is causing significant difficulties for us.

Could you please help us resolve this problem? We would appreciate any guidance or troubleshooting steps you could provide.

Thank you in advance for your time and assistance. We look forward to hearing from you.

Kind regards, Exterra

It's very odd. Normally moving an email, say from the Inbox to the relevant year's archive, takes "no time at all".

Which is true for all the mailboxes shown on the attached screenshot, EXCEPT for the four at the bottom. Moving even one message from Inbox to Yiddish can take ten seconds or longer (with the dreaded "Not Responding" occasionally). Moving something in the opposite direction is also screwy, only from those four.

I had thought that it was because they're rather large. This first started when there were just Yiddish and MSW, and I split off most of the earlier years into the archives shown. To no avail.

It's only an annoyance, but I'm puzzled about how such a thing could happen.

Also very slow tagging or untagging a message just in those mailboxes.

Moderator Notes:

• need a performance profile https://support.mozilla.org/en-US/kb/profiling-thunderbird-performance

I'm not sure how to make a feature request, but here is one. Can it be made easier to sort message filters alphabetically? I currently have over two hundred of them, because each site I sign up for gets a unique email alias, and I set up associated filters for them (each goes into a dedicated folder in my Inbox). It's a pain to manually sort them in the list.

Since yesterdayevening I am experiencing problems with connecting to imap.one.com with all four of my accounts in Thunderbird 157.0.1 (64-bits). It says something like "Connecting to the server at imap.one.com with username XX@XX.XX failed" (translated to English) Mailsystem at one.com (webmail) and in my Android (Bluemail-app) works fine. I tried to fill in the right passwords, even changed a password and tried the new one, but still no effect.

Settings: Servertype: POP-mailserver Servername: imap.one.com Port: 995 Username: emailadress

Connectionsecurity SSL/TLS Authenticationmetod: Normal password

I use the release-update-channel (if that is usefull info?)

What can be wrong?

I have three separate Yahoo email accounts. I set up Thunderbird to link to each Yahoo email account separately. It worked fine for a year or more. On 5/25/26 one of the three Thunderbird email accounts stopped downloading emails from Yahoo. I could see at the bottom bar Thunderbird indicating that is was downloading 1 of XX emails, but never actually downloads them. There is no error message. I checked the Yahoo email account to verify the number of emails I am missing from Thunderbird and the number is correct. I can see the emails in Yahoo. I'm the only person using Thunderbird, so no changes have been made to previous settings for retrieval. I confirmed Security and server settings for Thunderbird in and out going emails, and Yahoo are correct. I tested the connection in Thunderbird, and the connection is successful. I tried to send an email from the Thunderbird account having issues, and the email was sent and received by the recipient. The recipient replied, and Yahoo received the email, but failed to download it to Thunderbird...along with all the other emails since 5/25/26. I unlinked the account and reestablished the link between Yahoo and Thunderbird, and still not fixed. I tried restarting the computer, with no change. I tried to send an email from Thunderbird to one of the other Thunderbird emails and it was sent and received. I made changes to Thunderbird to force the download of emails, and it still wouldn't do it. I turned off my antivirus, closed Thunderbird, and restarted it, and that didn't change anything. The capacity of emails on the email in question only has 739 emails, so it's not over the limit and I have plenty of storage capacity. Thunderbird is set to save emails, Cookies and cache were cleared, no change. I ran the folder repair feature in Thunderbird, but there was no change. I compared all the settings between the other Thunderbird emails that are working against the one that isn't, and they are all the same. There was a suggestion to close out of Thunderbird and delete the "Global-message-db.sqite" file from the Thunderbird profile in case it was corrupted, and it would recreate this file when Thunderbird was restarted. The file was recreated, but it didn't fix the problem. There was mention that a suspicious email in Yahoo might be blocked by Thunderbird, so I placed various emails in the spam folder, and it didn't work. I did find one email in the Yahoo spam folder that was dated before 5/25/26 and moved it to the Yahoo inbox. Lo and behold, that one email downloaded to Thunderbird. So there is something within Thunderbird preventing emails from downloading after 5/25/26. I've read many people complain about similar download failures with no solid fix. Someone mentioned it fixed itself on a day, but then stopped again days later. Someone else mentioned Yahoo changed its password protocol to transfer emails, but that doesn't make sense since the other two are still downloading based on the "old" password protocol. I'm at wits' end. Thanks for reading all of this. I hope someone has a solution.

Today TB froze during start up. No problems yesterday.

I deleted global-messages-db.sqlite and restarted TB. Now it is frozen with a "Loading messages". Maybe it is rebuilding indexes and this takes a long time and I should be patient.

Maybe my In and Sent mail boxes are too big? If so, how can I safely prune them?

TB is becoming increasingly unstable for me. It was very reliable before about a month ago.

I doubt my AV is the culprit because AV has not changed today.

Thank you one and all.

I like the new support for Outlook. Thank you very much. This was the first year that I did not spend >16 hours rebuilding accounts each January. It is also nice that this support automatically transfered incoming emails to the Local Inbox.

Just recently, Spectrum Internet dropped POP3 support and I was able to setup IMAP.

Gee, It would be nice if there was just one more checkbox in the Account Setup which would automatically transfer IMAP messages to the Local Inbox.

Can this be added to the wish list?

Windows 11, Dell laptop, Thunderbird Meadow 153.4.0, yahoo mail configured as pop3 (i like to keep messages on my laptop). I was having trouble with mail getting "stuck" on downloading the past week or two, sporadically. It would load maybe 13 of 90, or 4 of 64, or whatever, then I'd get a "Connection to server timed out" message. I went online to the yahoo mail site to look for some offensive email that was trying to load and delete it; deleted about 50 of the messages that would've been sent to Thunderbird, then tried again. Did this a few times. Today it started where it wouldn't even load 1 of 34, or 1 of 60, or 1 of 96 as the day went on, would just time out on trying to load the first one.

Tried changing to IMAP temporarily, didn't help. Switched back. Didn't help. (Restarting each time I'd change this). Finally resorted to deleting the account (and all of my folders and filters! argghhh!) and re-adding it. Let Thunderbird automatically configure it for pop3. I did change the setting to not have it delete the messages on the yahoo mail server once loaded into Thunderbird.

Seemed to help, and it immediately tried to download the 3800+ messages that I've saved on the yahoo mail server. Only got to 1900, then stopped and timed out.

When I ask it to download new messages, it's back to the same thing - tries loading 1 of now 2007 or something, and can't get past 1. Times out.

Notice the version number above; it was much older, and I've since updated it 4 times to bring it up to where it is now where no additional updates are available at the moment. So as much as I'd like to blame it on an update, I hadn't had any automatic updates for a long time, so it wasn't that, and getting the updates now hasn't helped either.

Any suggestions?

When Mozilla was started this morning it came up with a page to donate. When I try to go around it to get to my email folders that show I have new email, I cannot. I have tried restarting the computer and the same thing still happens. How can I get past this to see my emails?

Byron

Hello !

I'm using Thunderbird in the dark mode. When I open the detail of an event in the agenda, the text is still written in black, on a gray background so this is not really readable (cf linked screen shot)

At some points I had similar issue with mails, but I found the little button "toogle dark mode for mail" that allow to keep the dark mode for thuderbird but show the mail with white background and black text.

Is there a similar functionality for the agenda ?

Thanks !

Ubuntu . Thunderbird snap 157.0.1 (64 bits) - 157.0.1 (64 bits)

Meadow Mozilla Thunderbird Snap for Ubuntu ubuntu-snap-build - 1.0

When i write a email and i attempt to join a file (CTR+MAJ+A or join button + File), nothing happens. It's the first time that i encounter this issue. I try to reinstall thuderbird but it was without effect on this issue.

Is it a new bug on this version ? Thanks