Thunderbird Community Forum

After getting fed up with the Outlook app on windows. I decided to switch to TB. Now i can recieve my mails but can't send. I don't Use VPN and also checked if Windows Firewall is screwing things up. But those are allowed

Without the following. Unable to login to server (SMTP) smtp.office365.com with username *****@hotmail.com has failed (Translated from dutch)

These are my Settings incoming IMAP server: outlook.office365.com, 993, SSL/TLS, OAuth2 authentication, User Name = *****@hotmail.com outgoing SMTP server: smtp.office365.com, 587, STARTTLS, OAuth2 authentication, User Name = *****@hotmail.com

Nach Update auf Release Kanal kein Geburtstagskalender mehr und Geburtstage werden nicht im Kalender angezeigt. Geburtstage in Kontakten vorhanden. Benutze keine Cloud und kein Google. Wie werden Geburtstage wieder im Kalender angezeigt?

Starting 2026 Comcast is moving all email over to Yahoo email. We will be able to keep our Comcast email address, but as of this writing I do not know what suffix Yahoo will add to my 2 accounts. Both of my Comcast suffixes are Comcast.net and that is how my email comes through now. I was shared a linked that I didn't from Comcast about the pending change. Will the suffix change from Comcast.net? I have attached the link that was shared with me.

I guess with your Comcast e-mail, you need to know this. Comcast e-mail is going away and users are being switched over to Yahoo e-mail sometime in 2026.

Upgrade your Comcast.net email experience to Yahoo Mail

https://www.xfinity.com/support/articles/yahoo-email-migration-overview

Optus (Australia) emails can't be sent or received by Thunderbird on my PC via my Optus wifi internet connection. I can use emails on my phone via mobile data with wifi turned off (different email client on the phone, though). Optus checked all the settings on my PC with me and they are all correct. They insist that it is a Thunderbird issue (doubtful, IMHO) and that I contact you. Is there an issue with Thunderbird connecting with Optus email? If so. is there any resolution to the issue? If not, can you confirm no problem from your end so I can get back to them (again!)

I am so glad I make regular complete backups. Version 146 is a hot mess. Highlighted subject lines flashing, folders disappearing, On the second start of Thunderbird 146 I could no longer connect to hotmail, gmail, aol, juno, yahoo, All broke. Ended wiping 146 off the computer with REVO, deleting the profiles and reinstalling 145 and recovering the profiles and messages I used with 145 from backups made 2 days ago. Running the latest version of Windows 11. No need to reply, just a fair warning.

Hello everyone,

like the title says, I want to set appointments in the calendar to private. I have shared calendars. Therefore, I need to be able to set some invitations to private.

In Outlook, it's no problem to set an accepted appointment to private, but in Thunderbird, this option only seems to be available for appointments I have created myself.

Recently my Thunderbird mail has been 'glitchy'.

Sometimes I receive audible alerts for emails, other times I don't.

Sometimes the number of new emails received is correct, other times it shows 4 new emails when, across all my accounts, the number is 2 (for example).

Are either or both of these known issues?

I also noticed when I was watching a live music stream on TikTok last week, I 'had' no emails for almost 2 hours. As soon as I left TikTok and closed my browser window emails 'arrived', one timestamped 45 minutes earlier. The settings for that account are set to check for emails every 5 minutes.

Could the Chinese be 'watching me' 😁 or is there another more innocent explanation?

Hello, I just upgraded to a new mac and installed a fresh download of Thunderbird. Things are working well except for trouble subscribing to this astronomy calendar: https://cantonbecker.com/astronomy-calendar/astrocal.ics It works OK on my old mac/Thunderbird setup, but not on the new setup.

Details: New system, where the astrocal calendar doesn't work: MacBook Air M4 2025, running MacOS Tahoe 26.1, Thunderbird 146.0

Old system, where the astrocal calendar works: MacBook Air Intel i5 2017, running MacOS High Sierra 10.13.6, Thunderbird 115.10.1 (64 bit)

My steps to subscribe are Event and Tasks tab click Calendar On the bottom left I click New Calendar This opens a Create new Calendar window. Click On the network, Next I select "This location doesn't require credentials" and "Offline support" I fill in the URL: https://cantonbecker.com/astronomy-calendar/astrocal.ics, then click Find Calendars At this point on the new Thunderbird I get the error: Could not find calendars at this location. Please check your settings. (screenshot) But on the old Thunderbird I get that astrocal is available, and it actually works.

Any ideas? Is it a bug in the latest version of Thunderbird?

Thanks,

Peter H. PS: The new mac's default Calendar app subscribes to the astrocal calendar OK. It's just the new Thunderbird that has trouble. PPS: The new Thunderbird does successfully subscribe to another calendar, of Japanese holidays https://ics.calendarlabs.com/54/44bd6152/Japan_Holidays.ics That makes me more confused as to where the problem lies.

I've lost all the contents of a folder in one of my TB accounts, including all subfolders. Mysterious, and all the more so since another email folder which wasn't a subfolder of this one is now in there as a subfolder. Everything else in that folder has gone. Nothing has disappeared anywhere else. I've trashed and rebuilt global-messages-db.sqlite but this hasn't helped, no difference. Any suggestions? Thanks!

I have down loaded thunderbird and it appeares to work OK but when I need to print out some times the printers which are loaded onto my PC do not show in the drop down box there is only the option to save to PDF Is this because I have not yet paid any money ? this is because I would like to try it first Alan W

I have been using Thunderbird for years for email accounts with Comcast (Xfinity), Yahoo, and gmail. Yesterday, I started having a problem with my Comcast accounts - when I sent a message, it went out, but I got an error message (attached) saying it couldn't save a copy to the Sent folder. Sending messages from my Yahoo account works fine. Sending messages from my gmail accounts, I get _two_ copies in the Sent folder (this is new).

I tried restarting my PC, and that didn't help. I tried Troubleshoot Mode, but that didn't help. I tried reinstalling Thunderbird, and that seemed to fix it, but then it started again. I tried compacting the folders, and that seemed to fix it, but then it started again.

I can connect to the Comast/Xfinity server fine, and things work. If I send an email from the server, a copy goes in the Sent file, and it then shows up in the Sent folder on my desktop. But emails that I send from the desktop don't show up in the Sent folder.

I am using a Dell XPS8950 with Windows 11.

Thank you for your help.

I was working on my email accounts when the messages in the inbox of one of my email accounts disappeared. The message count on the top left of my inbox display says 0.

How do I get them to show up again.  I am using Thunderbird on Mac OS 15.6.1

Hi everyone - and big thanks in advance for considering my request: I have/ had windows 11 on my old machine and windows 11 on my new machine; because my 'old computer' is not running anymore at all (liquid damage), I can no longer start Thunderbird and follow the 'export tool function' (https://support.mozilla.org/en-US/kb/thunderbird-export) and thus can only do the manual transfer (https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer); I didn't think that I would need to go through the export tool steps when I saved the Thunderbird profile folder regularly as backup on the cloud; yet when I started Thunderbird on my new machine following the above steps by moving the Thunderbird profile folder manually, the result is that - although Thunderbird is 'running' and the mailbox is functioning properly - the key folders are empty (i.e. the sub-folder structure is completely lost, in fact there are no individual emails at all); the issue seems to be that the size of the Thunderbird profile folder is too large (the "Profiles" folder has a size of 20.5 GB) for doing this transfer via copy & paste of the Thunderbird profile folder from the cloud (I also tried USB) to the new machine; I understand that the size issue via the manual transfer could be 'overcome' just by starting Thunderbird on the 'old machine' and following the above steps explained under mozilla support; yet that's no longer an option; what could I do please?

I am using 140.6.0esr (64-bit) and Windows 10. My Inbox disappeared. I was in it with no problems. Then I noticed two problems. I couldn't open new emails. It said connecting to server or loading content but email was blank. Also when I sent an email it could not copy to my sent folder due to network or file access errors. I could open and read all the other emails in my Inbox, just not three new ones. So I selected Inbox properties and repair. After the repair, my inbox is completely empty. It had thousands of messages. When I do a search for common emails I know were in my inbox, it only shows emails from subfolders. When I go to Inbox properties, it says number of messages: 0

Is there any chance I could talk with someone? Or that someone would call me? I'm not experienced in Thunderbird or email settings. And I don't like having to do it online. Richard Higgins Concord Mass

Running Thunderbird 140.5.0esr

This has been happening for a few weeks now somewhat randomly. The folders under Mail for one of my accounts keep moving around and are not in alphabetical order anymore. Most folders are OK, but a few either jump to the top of bottom of the list. I can manually drag them back, only for different folders to do it the next time.

The folders in questions are 2 levels down from Mail.

1) I need help in correcting the problem of why I am unable to send an email to someone and also 2) why all my emails this morning are going to ecurtis@neb-sandhills.net, which is the same consolidated website, and nothing coming into ecurtis@nebnet.net

Steps to reproduce the problems:

Perform a Global Search (ctrl + K). Search for any string. Just make sure there is at least one search result. > Click "Show results as list". > Right-click on the search result in the Message List Pane. (Please see the footnote.) > The pop-up context menu has two problems:

(1) There are redundant dividers. (Please see the first attached image.)

(2) Hover the mouse over "Tag". The pop-up submenu is incomplete. The menu includes "New Tag" and "Manage Tags". However, "Remove All Tags", "Important", "Work", "Personal", "To Do" and "Later" are missing. (Please see the second attached image.)

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These problems (redundant dividers and incomplete submenu) also occur in Troubleshoot Mode.

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These problems only occur after using Global Search and clicking "Show results as list".

If I right-click a message in the Message List Pane of a regular folder (such as the "Inbox" folder or "Templates" folder), the pop-up context menu displays correctly: There are no redundant dividers, and the submenu of "Tag" is complete. (Please see the third attached image.)

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Operating system: Windows 10.

Versions of Thunderbird: 140.3.1esr and 140.6.0esr. I was using 140.3.1esr, and currently I am using 140.6.0esr. Both versions have the same problems.

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Footnote: When I right-click on the search result in the Message List Pane, the following error messages display in the Error Console (please see the fourth attached image):

Uncaught NS_ERROR_FAILURE: Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIMsgDBView.getThreadContainingIndex]        mailCommon.js:647
    isCommandEnabled chrome://messenger/content/mailCommon.js:647
    fillMailContextMenu chrome://messenger/content/mailContext.js:340
    onPopupShowing chrome://messenger/content/mailContext.js:146
    handleEvent chrome://messenger/content/mailContext.js:133
    _onContextMenu chrome://messenger/content/about3Pane.js:5235
    handleEvent chrome://messenger/content/about3Pane.js:4758
    init chrome://messenger/content/about3Pane.js:4712
    async* chrome://messenger/content/about3Pane.js:170
    async* chrome://messenger/content/about3Pane.js:139

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The fifth attached image shows mailCommon.js:647.