Thunderbird Community Forum

thunderbird Is working fine, but this message crops up every few minutes, and requires 4 - 8 Cancel clicks. I've tried "Open anyway", I've deleted and reinstalled the app several times, and tried the terminal command "xattr - cr" and dragging the app into the window. Is there a proper fix for this. V. grateful for any solution. TIA Brian

Hello, since friday, 6.2. thunderbird does not launch new (and also not completely all older) Emails anymore. So I can't see all my recieved and send E-Mails. In all my 3 Mail-Accounts froms different providers it does not work anymore, without changing anything from my side I know. But from my handy, where I use google-Mail, it works.

I already checked synchronization settings and repaired the E-Mail-folders.

So, are there any technical defects or problems with thunderbird, an update for instance that caused trouble for instance? And what can I do, to make it work again? Atherwise I would have to quit thunderbird and change my Host.

Looking forward to your response and already thanks for support, all the best, M.

I was using a web mail client and it deleted my inbox. I have a backup of Inbox and Inbox.msf file on my local computer and keep copying it into the correct folder, but every time I start Thunderbird, it syncs from the server down and deletes all the messages in my inbox file.

How do I tell it to sync the local messages back up to the server or is there a good/better way to do it?

Problem with recurring events in the caldav (external) calendar. If you delete one instance of an event (today), events for previous days are automatically created.

Thunderbird ver. 140.7

The Hilton hotel reservation produces the following .ics file (with some edits for privacy), which fails on import. Deleting lines like the second block will import correctly. I can make this edit when needed, so this is more of a bug report than a question. I have not tried to narrow it down more, this is something I do once every couple of months.

BEGIN:VCALENDAR VERSION:2.0 METHOD:PUBLISH PRODID:-//Microsoft Corporation//Outlook 11.0 MIMEDIR//EN COMMENT:via ics.agical.io CALSCALE:GREGORIAN BEGIN:VEVENT DTSTAMP:2026xxxxT035151Z UID:2026xxxxT035151Z-1969360351@ics.agical.io DTSTART:2026xxxxT220000Z DTEND:2026xxxxT180000Z ORGANIZER: SUMMARY:Your Upcoming Stay DESCRIPTION: LOCATION:Hampton Inn %26 Suites by Hilton Wheat Ridge Denver West\, 4025 Clear Creek Drive\, Wheat Ridge\, 80401\,US BEGIN:VALARM TRIGGER;VALUE=DURATION:-PTM DESCRIPTION:Agical Alarm: Your Upcoming Stay ACTION:DISPLAY END:VALARM X-MICROSOFT-CDO-BUSYSTATUS:BUSY END:VEVENT END:VCALENDAR

BEGIN:VCALENDAR VERSION:2.0 METHOD:PUBLISH PRODID:-//Microsoft Corporation//Outlook 11.0 MIMEDIR//EN COMMENT:via ics.agical.io CALSCALE:GREGORIAN BEGIN:VEVENT DTSTAMP:2026xxxxT035119Z UID:2026xxxxT035119Z-224582756@ics.agical.io DTSTART:2026xxxxT220000Z DTEND:2026xxxxT180000Z SUMMARY:Hampton Inn %26 Suites by Hilton Wheat Ridge Denver West\, 4025 Clear Creek Drive\, Wheat Ridge\, 80401\,US END:VEVENT END:VCALENDAR

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.

Hello,

Need To Know:

I have used Thunderbird (TBird) for many years. Recently, I moved TBird data from a Dell Inspiron 530 Win 7, to Alien Arora 1250. Unfortunately, the passwords would not go, so I copy and pasted the data for 10 email addresses. All worked well, until 5 days ago when I could not log into the ISP.

Since then, 12 ISP tech support people gave me 12 different was to fix the login problem. The 'logging in' kept trying to login. The only way to stop it is to close TB and restart it. The same happens with all 10 accounts - can't login.

I followed instructions to the letter and nothing worked. Later, a tech at ISP said they have had a lot of complaints from people with Tbird and said it's Mozilla's fault. They all said they don't support Thunderbird. They only support webmail. One even suggested I delete all my cookies. Of course I'm not going to do that.

You would not believe the amount of crazy ideas I was given.

Here is the core problem:

I used both Pop and IMAP depending on the email account. TBird was great with POP and IMAP either.

I changed all the passwords as instructed. I followed the Step-x-Step settings on the ISP web site

The ISP, Rogers, took over Shaw. Rogers, I'm told, dropped support for 3rd party email clients and requires customers to create a new email on their Webmail host. Webmail is WEBmail because it is not Email.

Testing Out TBird:

1. On the old Win 7 TBird (Ver. 68.1.1 (32-bit)) Email works with both POP and IMAP settings.
2. On the new Rig, Tbird (V. 147.0 (64-bit)) worked for a while.

What Happens: -- Due to the issues, I set Tbird to not:, -- Check for new messages at startup -- Check for new messages every -- Automatically download new messages -- Fetch headers only

The two ISP are Rogers Rogers and Shaw <--- just redirects to Rogers. But webmail.shaw.ca still works.

My Rig with the issues: Alienware Aurora Desktop 1250 Intel i9 Ultra Nvidia RTS 5080 Memory 32 GB DDR5 Storage 2 TB SSD + 2Tb HDD Thunderbird Version-147.0 (64-bit)

Is the ISP correct, that Thunderbird may be the core problem?

Thanks for your volunteering - where would we be without you, ~r

Add outlook email account in Thunderbird app on Macbook does not strictly go through microsoft 2-step verification process. In stead, microsoft verification window flashes away instantly and Thunderbird window takes over. Although OAut2 is specified, the set up is not right. Sending email from outlook account takes about one minutes. Sometimes if it takes longer time, sending email will fail.

I have been using ThunderBird on Linux Mint for some time now. I am using Outlook.com for emails, calendar and contacts and I sync with another laptop and mobile phone. All fine until a few days ago when I noticed calendar events were not syncing with my phone. I found one calendar event in ThunderBird had an error when I manually synced with TbSync. The error report did not say anything specific. I deleted this calendar event and TbSync ran successfully uploading 2 events that it had not uploaded due to the calendar sync error. I then wanted to manually recreate this calendar event in ThunderBird. When I clicked on "New Event", the Calendar New Event pop-up window did not appear. When I minimised the ThunderBird window, the New Events was not behind it. The ThunderBird icon pinned to the panel had a "2" in the corner. When I hovered over the ThunderBird icon in the panel, it showed both the ThunderBird window and New Event window preview. When I selected the New Event preview window in the panel, it still did not become visible. All I could do with with New Event preview window in the panel was click in the 'X' to close it. I checked for Lightning Calendar Tab add-on updates. It was up to date. I check the settings. All OK. I disabled and enabled this add-on. Still not working. My Windows habits made me shutdown and restart my device. Still Not working. When I checked the other ThunderBird functions, New Event pop-up windows appeared for Emails and Contacts but not Tasks which had the same symptoms as the Calendar.

Hello,

After today's Thunderbird update for Windows 11, over half of the folders in the local folder are no longer displayed. However, the folders are present in the backup folder on an external hard drive.

What's causing this?

Best regards, Steffen Liebig Bautzen, Saxony, Germany

All the folders, Inbox included, disappeared from one of my outlook accounts. It's OK everywhere else so I decided to remove and re-add the account in Thunderbird but now I can't add it again.

I get the error. "Authentication failed. Please check the username and password Exchange auth error"

I know the Username and Password is correct.

Solution appreciated, please.

My contacts address book is provided by Apple iCloud, of which I have added contacts with avatars for every contact I've received legitimate emails from. However, Thunderbird fails to render these avatars. The result looks like the attachment. Perhaps Apple is using HEIC for them?

I have a local folder which has 90 folders within it. These are folders brought over from Eudora (the mail system I used before Thunderbird). It would help me if I could easily move all 90 from their current "Eudora" folder to the big "main" folder that Thunderbird has. To make it clear what I'm asking, here's an example, using two folders, Danbury and Fritz.

D (folders whose names begin with D) Eudora folder, which has two folders - Danbury and Fritz F (folders whose names begin with F)

Is there any way to move the 2 folders that are currently within the "Eudora" folder so that they're "first level" folders. In other words, Danbury would be among the "D" folders and Fritz would be among the "F" folders.

The only way I know to achieve this is by manually creating the new folders, moving the items from the old folder to the new folder, and then deleting the old folder. This is cumbersome.

I am setting up Thunderbird on a Win10 machine, and am having a lot of trouble adding accounts that I did not have on the two Win11 machines I have set the same accounts up on.

When adding my 2 GMail accounts, after clicking "Allow" on the OAuth popup the button would go grey the window would stay open and not close, and the account would not be added.

Changing the general.useragent.compatMode.firefox option to TRUE allowed me to progress and finally add those accounts.

I am now having the same trouble with my @hotmail.com account. When I add the account, the dark blue OAuth window pops up, but is completely empty, and there is nothing more I can do.

Things I have tried

• Reverting the above config change
• Checking that cookies and JavaScript are enabled
• Checking there is no saved password
• Used both the Account Hub and the default dialog, with the same effect.

Thanks in advance!

A search showed that others have experienced this same error message, but as far as I can tell, they all were unable to access their email. These messages began appearing about a month ago. They pop up in Troubleshooting Mode. They did not in Windows Safe Mode. AVG and ZoneAlarm are not the culprits.

Tried to send a rather routine email on Outlook account. Wouldn't send. Checked settings. Outgoing server, which I set to smtp-mail.outlook.com, had "magically" changed to an outlook365 server. Switched it back. Still wouldn't send. After some investigation and some suggestions from copilot, I noticed my Surfshark VPN was on. I don't run it all the time, just when I need it to log onto blocked sites. Copilot said: Surfshark is notorious for silently blocking outbound SMTP ports — especially 587, 465, and 25. Switched outgoing port to 465 as suggested by Surfshark support and tried to send again, without Surfshark on. Still wouldn't send. Finally went to outlook.live.com to send the message. Went OK. Kinda baffled. Anyone help?