Thunderbird Community Forum

Hallo, ich habe vorgestern ein neues Win11 aufgesetzt und dann die neueste Version von Thunderbird installiert. Mir ist jetzt aufgefallen das sich die E-Mails nur mit einem Doppelklick öffnen lassen und das dafür ein neues Fenster aufgeht. Früher waren die Mails mit einem Klick zu öffnen und der Inhalt wurde auch direkt unter der Mail angezeigt . In den Einstellung steht der Doppelklick nicht in der Auswahl sondern als einzige Möglichkeit. Gibt es da irgendeine Möglichkeit um das anders einzustellen, einfacher Klick und direktes anzeigen ohne extra Fenster? MfG

Hello, the day before yesterday I set up a new Win11 and then installed the latest version of Thunderbird. I have now noticed that emails can only be opened with a double click and that this opens a new window. Previously, emails could be opened with a single click and the content was also displayed directly below the email. In the settings, double click is not in the selection but is the only option. Is there any way to set it differently, single click and direct display without an extra window? Best regards

Subject: Persistent Column and Folder Layout Issues — Not Being Saved Between Sessions

This is a follow-up to my previous support requests regarding two ongoing problems that significantly impact daily usability.

Column Settings I manage multiple accounts, and my preferred column layout is: Starred, Read Status, Attachment, Subject, From, and Date/Time. I do not use Threads, Correspondents, or Spam Status columns. Despite setting these preferences repeatedly, Thunderbird fails to retain them. Every day I must spend time reconfiguring columns across some or all of my accounts — the state varies unpredictably from one session to the next. This is a persistent, daily frustration that costs meaningful time. Most other major email clients save and reliably maintain column preferences. I'd expect Thunderbird to do the same.

Folder Panel Layout Two problems occur regularly when Thunderbird loads:

Folder order — Standard system folders (Inbox, Sent, Drafts, All Mail, Trash, Spam) should appear at the top of each account. Instead, Sent, All Mail, Trash, and/or Spam are frequently scattered among custom folders, with no apparent consistency.

Folder expansion — Most or all folders load in an expanded state, exposing every nested sub-folder regardless of whether they contain unread mail. This creates unnecessary visual clutter and requires manual collapsing each session.

Again, this behavior is uncommon in other widely-used email clients. Summary These are not one-time glitches — they recur daily and represent a significant usability gap. I'd appreciate confirmation that these are known issues being tracked, or guidance on a reliable fix. Reformatting the interface every morning is not a reasonable expectation for users.

I've been using Thunderbird on Windows 10 since last year sometime. Currently I'm on version 151.0.1.

I've 4 x mailboxes here and since yesterday, 3 of them show me an unusual message when checking for emails. I tried attaching a screenshot but although the screenshot uploaded, I couldn't find a way to insert it here. But the message says Unable to write the email to the mailbox and asks me to check if I've write privileges (which I have) and to cheek the available disk space.(currently 101GB free).

The message is happening 2 or 3 times each day and lasts for about half an hour, then everything works fine again. Has anyone else seen this??

I use Thunderbird on dark mode, so by default, unformatted text (where I haven't explicitly set text color) appears as white text on a black background in my compose window. The same unformatted text, when sent to someone viewing it in light mode, appears as black on white to them and remains readable. When I use white text in my compose window, it looks identical to me, but remains white when sent and is thus unreadable white-on-white to those using light mode. Is there something in the composition window that indicates whether I'm typing with formatted or unformatted text? (No, the color selector tool does not do this. When typing unformatted text, it displays the last selected colors, regardless of whether they are being used.)

If there's no way to distinguish this, could someone please add a UI element for it?

I've been a Thunderbird user for years without problem. However, since May 22, three specific messages continually reappear after deleting them from my Inbox.

I keep my Inbox empty and it stays that way, except for these 3 messages. Removing them from the Trash folder has not solved the problem.

My email provider is netaddress.com via POP3 account. I signed on to look at my inbox on their site via a browser, and the messages aren't there.

I have tried repairing and compacting the inbox, but the messages continue t reappear.

Do you have any other suggestions?

TIA.

ChuckM

After a recent update to Thunderbird (months ago), I found that when I search through my emails by name, it will find those emails and list them for me. But when I go and click on one of those found emails, it arbitrarily brings up some unrelated email - it never brings up the one that I click on.

How can we fix this? Thanks. Dr. Howard Neufeld

I setup an address book for a club so I can send BCC emails but it won't use the club address book! I had one in my old computer. So I try to send an email, click BCC and start typing the club name and it doesn't appear! In my previous computer it would find the club address book and insert it in the BCC line! This new one doesn't do that!

I accidentally deleted a good number of my emails from my local Pop3 server account. I don't delete my emails from my gmail server so I can just redownload all my emails but cannot remember the prefix needed to do it.

If I recall correctly I go under settings for my email account, then go to server settings and add the prefix to my email shown in the Username field under the Pop Mail Server Section.

Can anyone remind me of the prefix?

It was like restore:[my email] or all:[my email].

I should have made a note of it as I cannot find it anywhere online now.

Why are many calendar events just disappearing? This has been happening for the last three months!! Calendar events were there yesterday, are gone today! I tried in protected mode and lost even more events. Now even more are missing. Several I have re-input over the last months, and they get gone too. What’s going on!! There are no addons, no sync. Nothing but Thunderbird. any one else having this bug?? What file are events stored in and how do I read them?? Any way to recover anyof these?? There is a lot of information and annotations, such as cancellations and rescheduleing and the whole bunch just disappeared? Many older events are still intact but I sure don't know for how long!!! My profile is on a separate drive and is accesed by both W10 and 11 for email and calendar. No problems except they are missing using either system!! It's a bug!! Anyone interested in looking at it?? Robert [edited email from community support forum]

Some mail in my spam folder is marked with the red flame spam icon, and some isn't. It's all spam -- that part is okay. Thunderbird has sorted everything correctly. But why wouldn't everything in the spam folder be marked as spam?

Hello, I have six calendars: five are hosted by one provider, Runbox.com, via SabreDAV, and one is hosted by a different provider, Apple iCloud Calendar. I am periodically seeing the error shown below on multiple calendars during automatic sync.

I have saved a two-day event history from the error console and can provide it on request, along with any other troubleshooting information that may be helpful.

I am technical by nature, but my programming experience was primarily with mainframes rather than personal computers. Could someone kindly help me troubleshoot this ongoing issue?

Thanks in advance.

Bill

10:34:53.958 An error occurred when writing to the calendar House! Please see below for more information. Error code: MODIFICATION_FAILED. Description: If you’re seeing this message after snoozing or dismissing a reminder and this is for a calendar you do not want to add or edit events for, you can mark this calendar as read-only to avoid such experience in future. To do so, get to the calendar properties by right-clicking on this calendar in the list in the calendar or task view. CalCalendarManager.sys.mjs:949:15

   announceError resource:///modules/CalCalendarManager.sys.mjs:949
   onError resource:///modules/CalCalendarManager.sys.mjs:803
   notify resource:///modules/calendar/utils/calDataUtils.sys.mjs:46
   notify resource:///modules/calendar/utils/calDataUtils.sys.mjs:73
   onError resource:///modules/CalCachedCalendar.sys.mjs:95
   notify resource:///modules/calendar/utils/calDataUtils.sys.mjs:46
   notify resource:///modules/calendar/utils/calDataUtils.sys.mjs:73
   notifyError resource:///modules/calendar/utils/calProviderUtils.sys.mjs:689
   notifyOperationComplete resource:///modules/calendar/utils/calProviderUtils.sys.mjs:662
   notifyListener resource:///modules/CalDavCalendar.sys.mjs:720
   doModifyItem resource:///modules/CalDavCalendar.sys.mjs:794

Here is an additional group of errors from the night before:

23:09:52.245 [calCachedCalendar] replay action failed: <unknown>, uri=https://dav.runbox.com/calendars/908506/bill/, result=2147500037, operation=[xpconnect wrapped calIOperation] 23:09:52.249 calendar: CalDAV: No response status doing webdav sync for calendar House CalDavRequestHandlers.sys.mjs:476:16 23:09:52.249 calendar: CalDAV: No response status doing webdav sync for calendar House CalDavRequestHandlers.sys.mjs:495:16 23:09:52.249 calendar: CalDAV: Error doing webdav sync: undefined CalDavRequestHandlers.sys.mjs:528:16 23:09:52.263 calendar: There has been an error reading data for calendar: House. However, this error is believed to be minor, so the program will attempt to continue. Error code: DAV_REPORT_ERROR. Description: There has been an error reading data for calendar: https://p31-caldav.icloud.com/204954917/calendars/home/. It has been disabled until it is safe to use it. CalCalendarManager.sys.mjs:952:16 23:09:52.263 calendar: There has been an error reading data for calendar: House. However, this error is believed to be minor, so the program will attempt to continue. Error code: READ_FAILED. Description: CalCalendarManager.sys.mjs:952:16 23:09:52.263 [calCachedCalendar] replay action failed: <unknown>, uri=https://p31-caldav.icloud.com/204954917/calendars/home/, result=2147500037, operation=[xpconnect wrapped calIOperation]

I added a new mail account and then after a week or so decided to remove it. But after removing it I kept getting a popup nag to enter a password for the removed account.

Hello, My Provider is vodafone. Since you updated Thunderbird, i can't send emails. This Problem exist since about 2 Month. Vodafone cant help me, because they said, it is your Problem. I need very quick help. I need emails for my business. Thanks

I've been seeing a doubling of *some* incoming messages, where a duplicate message comes very soon after the first one. For example, two incoming messages were received at:

Sun, 07 Jun 2026 14:03:10 +0000

Sun, 07 Jun 2026 14:04:31 +0000

So the second message came in about 1 minute and 21 seconds after the first, and not because of anything I did (as far as I know). But then that was it, no third message came in.

This isn't really a bug, as nothing is harmed, just a repeated message. Any thoughts would be appreciated.

I was recently forced to change my gmail password. All of the help messages I found tell me that after I change my email password I have to save the new password to Thunderbird and I don't know where to save it.

When i try to update my schooles secure mail, i get the nev certifikat and the Root, and Ca1 under autoreties and give it the right rights but it keeps giving me this error message " Certificate verification failed with the following error: The peer's certificate issuer is unknown. (Error code: SEC_ERROR_UNKNOWN_ISSUER)"

Today I created a subfolder and moved many precious e-mails there. That move was successful. Thereupon I shut down my Thunderbird and my computer. When I restarted my computer and my Thunderbird the folder which I created was empty. Please let me know how I can recover the e-mails. Thank you.

I'm using gmail/outlook/hotmail email addresses on a new win11 laptop with Surfshark VPN and getting email up & running is the last major set up issue. I am having issues with both send & receive emails across all addresses. I get some functionality if I pause the VPN (not ideal!) but not total. I have tried the Surfshark bypass function for Thunderbird but without success.

I have had no issues with this setup for many years on win10.

Using Outlook (one email address) on the web with the Surfshark Chrome extension I can both send & receive.

1. what should the IMAP & SMTP server settings be for gmail/outlook/hotmail? 2. are there any known issues with Thunderbird/Surfshark? 3. are you aware of any issues with gmail/outlook/hotmail blocking Surfsahrk?

Alan Burdis

When I get spam email in my inbox, I mark it as SPAM. It will arrive again in a couple of days. Why does it come into my in-box still? Its marked as SPAM in my In-BOX!

I don't want to keep touching junk email!!! its a huge waste of time. I cannot find the settings on how to make that action happen.

Please advise. If this isnt possible I will unfortunately be leaving your platform after decades of use. Yes I have donated several times over the years. Not get rich money, but it all helps.

Dean