Thunderbird Community Forum

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 trying to setup Netzero email on Thunderbird. I get the error message, posted in question. Outgoing mail works but can't load inbox messages. I got the following error message when I first started Thunderbird - "The STAT command did not succeed. Error getting message numbers and sizes.Mail server pop.netzero.com responded: POP access disabled"

Abbreviations ( Nat'l for National) locks up a send function. A mis-spelled word locks up TBird when I click send. For either instance the mouse will not click on anything except the red X delete.

After several hours of trying to figure out why a folder didn't show certain messages, I realised that I had selected a Custom View a few days ago and it still applied quietly when I selected that folder. This is not the first time I fall for it. Is there a way TB would show that a Custom View filtered out some of the messages? Eg the Custom View button could be depressed, or the background in the messages pane would be different, or something. As it is now, I think I won't use the feature again and save myself hours of scratching my head in the future.

I was having trouble with Thunderbird outgoing mail. I changed some settings and it still didn't work. I tried to log in to Thunderbird and now cannot log in at all. I have 25 years worth of email in this account!

Cannot send or receive email all of sudden in Thunderbird. When I the click the messages icon, nothing happens, and I get "Could not connect to server mail.twc.com; the connection was refused". When trying to send a m,message I get "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mail.twc.com failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again." No settings were changed and everything was fine when I put the computer to sleep. This happens on both a Win 7 and 11 machine Email is a Time Warner (now Spectrum) Road Runner account (twc.com). Spent an hour with Spectrum, and they say this is a third party (Thunderbird) issue. A friend has the same setup, and is having the same problems that started at the same time. Win 11 version 150.02 Win 7 115.18.0 (latest available for win 7)

Appreciate any help....

156.0.1 RSS subscriptions function normally Clicking on "Manage Subscriptions" button in "Account Settings - RSS" does nothing. Running in Troubleshooting Mode doesn't help.

Thanks,

Steven

For a few days I'm having trouble with Asana mails (notification mails informing me about replies, comments, etc).

Clicking on the mail to view it freezes Thunderbird for a good 5 seconds while one CPU core spins at 100%. This only happens with Asana mails (or at least I haven't found any other problematic senders).

I guess it's a problem with validation or parsing of the mail's HTML content. But I don't know how to debug this.

I can't pinpoint exactly when it started happening, but it was around the time I've switched to the [new snap release track](https://support.mozilla.org/en-US/kb/channel-choices-thunderbird-snap-and-flatpak#w_snap-channel-changes-in-2026). But since this happens with Snap and Flatpak I think the culprit may be the 153.0 update.

Things I've tried:

• Clearing cache and msf files.
• Troubleshooting mode with add-ons disabled.
• Reinstallation. Creating new profile + importing old data.
• Switching from Snap to Flatpak
• Switching Message Body display to Plan Text or Simple HTML.
• Disabling HW acceleration.
• Checking console for suspicious output.

Anything I can do to create handle the problem or collect information for a proper bug report?

I use a Thunderbird add-on named "Full Address column" on my Windows 11 system. (TBird version 152.0.1, moving soon to 156) It adds a field with the heading: Sender (@) I would like to filter incoming email based on that field. I see that I can edit a filter to customize a Message Header. Should I use Sender (@) or just Sender Or something else ? The use case is rare enough that I thought I'd ask here before experimenting.

My Thunderbird connected to my gmail is running slow. Thunderbird is not running slow on my other (non-gmail) account. It takes 10-15 seconds for an e-mail (from gmail) to be deleted or moved within Thunderbird. I have tried "compacting folders" and "repairing folders" and that does not help. Please help!

My email account is handled by a university that uses Office 365-based Microsoft system for email accounts. My institution now requires that email client programs us MS Graph for authentication. Does Thunderbird 156.0.1 have this capability?

win11 :Thunderbird will not launch, It appears the issue is a Background Process labelled "Thunderbird" which is unresponsive to "end task" in Task Manager. Will launch after reboot.

I have no clue as to how Tbird into this state, but it has happened more than once

Thunderbird Version 156.0.1 Build ID 2026092215180

Hi there :-) Thunderbird on Windows 11: When I, by accident, misspell an e-mail address in the "mail to" column and realize this afterwards, it becomes impossible to re-enter the correct spelling of this text, not even after deleting it completely. It re-appers already after recognising its first letters and completes it over and over "intelligently" - bu wrongly - again. No matter if it is an address chosen from the contacts, or a newly written one. It there a way to solve this problem? Thanks for your help!

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.

The issue is that the text I type into the top level of account settings, which has Account Name, and Default Identity, doesn't save. Initially I entered the email address and Thunderbird found the correct details, but I was creating seven new accounts and was going to come back later and fill in the details. However, the details on this page don't stick, wand it reverts to blank entries (as shown in the attached image), and each account's name defaults to the email address. It's awkward because if I create a new message it won't add a signature because that gets cleared with the other details on this page.

This might be related to an earlier question I asked Delete Account button doesn't work. since it's on the same page as the DELETE button. This suggests to me that there's a script engine that I'm missing on my PC. This is only a guess. I use Fire Fox as my main browser, and Vivaldi as a backup. As I say, this is only a guess.

Installed Thunderbird in August 26. Successfully added Outlook and Gmail accounts (send and receive)

On a roll I then tried to migrate from Plusnet to Greenby. Can successfully receive emails via IMAP.plus.net server. But could not send mails from Greenby (other accounts still OK)

Traced problem via forum query 31???? to inability to create a new SMTP server for outbound mail. After entering all data in the outbound server there is no response whatsoever to clicking add button (ie no error messages or servers added to SMTP list)

Then tried to delete the partially active Greenby account via clicking delete button in account setting window. No response. Account still present.

Does anyone have any suggestions to solve this before I try the doomsday action of deleting and reinstalling Thunderbird.

TIA Phil

Bonjour. Plusieurs onglets correspondant aux messages ouverts dans thunderbird se sont fermés brusquement. Je voudrais savoir comment les réouvrir. Merci de votre aide.

Hello Since I changed my TB Android incoming server setting from POP to IMAP, Android has repeatedly reported app crashes. It asked me to clear cache, which I tried. See img attached. Eventually it said it was putting the app into deep sleep. Yesterday, after I sent an email to a gmail acct I was unable to find a copy of the email in a sent folder, there wasn't any Sent folder. There were only 2 folders, Inbox & Outbox. I expected there to be Sent & Draft folders. Eventually I discovered via Manage folders an Inbox.sent & Inbox.drafts. So I tried to change folders so Sent & Drafts are at 6the same level as Inbox & Outbox. Yesterday there were approx 26 emails in the Inbox. This morning there are 3 new emails in the Inbox & the 26 emails have disappeared & Inbox.sent, Inbox.drafts have disappeared. The 3rd & 4th attachments show the current folder settings. My TB Desktop incoming server serting is POP. Please tell me what I am doing wrong & what I must do to be able to see all my emails, received & sent. Thank you

I am using Thunderbird on Windows, and I want to hide the yellow “Your privacy is protected” notification bar but still have the privacy protection enabled.

I tried to use a userChrome.css in my Thunderbird profile; here is the path; (C:\User\AppData\Roaming\Thunderbird\Profiles\lz1po89m.default-release\chrome\userChrome.css). I also set toolkit.legacyUserProfileCustomizations.stylesheets to true, but the customization does not work.

If anyone can please help and/or advise me on the correct procedure or CSS selector for this version I would be very much appreciated.