Thunderbird Community Forum

I have used Thunderbird with the same email account for years, creating subfolders and moving emails to the subfolders with no issues.

With Thunderbird 153.0.1, after creating a new subfolder in the account, when attempting to move emails to the new folder, I receive the following error:

"Thunderbird: The current command did not succeed. The email server responded: APPEND invalid flag list"

MY second email account (droulston@btinternet.com) stopped working 3 days back (it has been OK for many years). I tried uninstalling and reinstalling but my password was not accepted.

As of September 3, 2026 all my new emails are going into a random folder instead of the inbox. This is also happening on my wife's PC plus and we are not getting the emails to our iPhones until we get out of Thunderbird. What has changed? This has not happened before.

Twice in the last fortnight Thunderbird has lost all email passwords - the Tools/Settings/Privacy and security/Saved passwords just leads to a blank box where the passwords usually are. Thunderbird will no longer collect email and keeps asking for passwords for email accounts. This happens even when the option to 'save password' has been selected. I think this is probably happening at the point when the PC is rebooted. Thunderbird version 153.1.1esr (64 bit) and Windows 10. Using System Restore has not resulted in recovery of passwords. Several different email accounts/email providers are involved - outlook.com, tiscali.co.uk and zohomail.eu. Broadband provider is Zen.

I notice that the Appdata/Roaming/Thunderbird/Profiles/w2anb37y.default folder contains a number of files named with such names as 'logins.json-8.CORRUPT' - with 'Date Modified' being mostly either 17th August or today 31st August - so it might look as though password data is becoming corrupted.

Can you assist?

James

My folders are in disarray and it is cutting into my productivity to file emails. I have tried but it in settings but it doesn't work. Many are in alpha order but there are 2 different two different sections of the same name, and some odd files end up in an alphabetized section.

For instance there are 2 different ZBV sections with other stray folders in the same area that should be in there own alpha folder area. It's a mess to find the right folder. I have to scroll up and own and look for the folder I need to file in. I would be happy to donate, and i have in the past, but I really need this to get fixed. Please, please, please...

I'd be v grateful for help as this problem's in an email needed for me to sue for libel.

I drafted an email containing >50 screenshots, but not as attachments. Current download speed 257Mb/s.

Looking at it just now, it's saved with many instances saying "may be an image of text that says" followed by a description. Or as attached.

I thought that if I sent it to myself it may display correctly, but it doesn't. There's no notification bar.

I have the following settings: • View > Display Attachments Inline: checked. • Privacy settings > Allow remote content in messages: checked (no exceptions).

After the latest update of thunderbird on 19-aug-26 I found that I could send emails but not receive them. After researching the problem I changed my server setting for imap to match what spectrum recommends, confirmed I did it correctly by spectrum. Test imap connection fails, but gives no information as to why. Tried 3 dirrent imap server: 1. imap.charter.ner 2. mobile.charter.net 3. mail.twc.com I confirmed with spectrum that I'm using the correct port number.

Is it possible to rill back thunderbird to the last release? Thanks for any and all help. I've used both google and duck duck go AI to look for answers.

I have two Tbird accounts pmcreativeservices@rcn.com has been mine for 20 years, and it's what I use for bills, banking, etc. The other account is PatriciaRosemoor@rcn.com and is only used to collect messages that come from my author website. Yesterday, I got a message from someone who tried but couldn't put a book up at Amazon and asked if there was something I could do about it. My trying to send her a message via the PatriciaRosemoor account is what started requests for my Primary Password. One a minute after I cancelled the last one. I tried the two passwords I knew I had, but neither worked. I got a request for a new password so I did that and it didn't work either. I kept going back to it all day yesterday uselessly. I found directions of what to do online, but it didn't match up with my Settings information. Please, if you can tell me how to fix this, I would be grateful. Or, if I can keep the thousands of emails I probably have, I could try deleting the account and recreating the account. The problem would be how to bring all my saved emails back. Thank you for your help. Patricia

Thunderbird widow is coming up on the sceen and says loading mesages. Does not happen. And it is not possible to promt. It is also impossible to quit the programme, I have to turn off the lap top. I have upgraded, seems to be ok. but the problem is still there. Geir H W

Copilot has prepared a message for me: Subject: Thunderbird always loads corrupted profile and ignores new profiles

Message:

Thunderbird is stuck loading the same corrupted profile and always shows the welcome screen, even when I create new profiles.

I used the Profile Manager via thunderbird.exe -p and created new profiles (“Clean” and “Clean2”). Both profile folders exist in %APPDATA%\Thunderbird\Profiles. However, Thunderbird still launches the same original profile every time.

Even when I select “Clean2” in the Profile Manager (with “Use the selected profile without asking” unchecked), Thunderbird ignores the selection and loads the old profile. Safe Mode (thunderbird.exe -safe-mode) also does not disable the welcome module.

This appears to be a profiles.ini corruption or a profile lock issue, because Thunderbird is not switching profiles even though the Profile Manager shows the correct selection.

Could you advise how to repair or reset the profile configuration so Thunderbird will actually load a new profile?

Thank you.

A hacker got into one of my accounts. All emails to all accounts do not get past the Yahoo and Google servers and I've only been able to restore service through principal account. How can I save my data and correct the compromised settings?

Hi,

I'm running the latest version of Thunderbird 140.12.1esr on 15.7.7 (24G720) on an M1 processor.

I'm witnessing Memory leak > Thunderbird who usually use 800MB jumps to Gb up to 60Gb

It makes this version unusable.

Here is a loom of the incident: https://www.loom.com/share/0b8e661b42d64d749d80adfd71fd1e04

+ a screenshot

Anyone can help ?

Best Olivier

I use to be able to get my charter.net email messages by going to the Thunderbird icon, but now I get an error message saying there is a connectivity problem. Please help.

I have not been able to get my emails today from Charter on my desktop. Everything was working fine yesterday but nothing in coming through today. It looks like it might load, message that it is downloading 1 of 26 and then says nothing to download. I look on Charter website and there are current emails to download but Thunderbird must have a glitch. I have been on the phone with Charter twice, all the settings are correct for incoming and outgoing ports.

I have looked at the settings in Thunderbird and they are correct. I can get the emails on my iPad and iPhone with the Thunderbird app but not the desktop.

Can anyone give me some direction of where to check next?

bob.fannon

Feb 14, 2026, 13:01 CST

I have used Thunderbird for a number of years with Plusnet (using POP settings) in the UK. However, Plusnet has transferred their support to a company called Greenby who have made a hash of it and offer very poor support. So, I want to use Outlook as the mail server but I am unable to send any messages via Thunderbird to the Outlook server. I can however download messages with no problems. The error message I get is :- Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) smtp.office365.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'

My default Outgoing Sever settings are :- Server Name : smtp.office365.com Port: 587 User Name: bob.fannon@outlook.com Authentication method: OAuth2 Connection Security: STARTTLS

I have tried deleting the Thunderbird account and re-creating it but still got the same result. I also tried to use my old Icloud account ( having first setup my App Specific password) but got the same result.