Thunderbird Support Forum

Hi I am having problems with Thunderbird, i’m not sure if it’s to do with a windows 11 update or something else. Thunderbird is not responding also at the start of the ‘not responding’ emails from one of my accounts disappeared and then gradually started to reappear but didn’t get up to date and now just not responding st all. I have tried various things to resolve this, uninstalling and reinstalling Thunderbird, doing this and opening my pc in safe mode, doing this and opening Thunderbird in safe mode. Deleting and reinstalling the latest windows 11 update, reinstalling the latest Thunderbird update. I don’t know what to try next? I read somewhere to delete your profile, after saving it, and getting a new profile but no idea how to do this. Any help appreciated.

I've been running Thunderbird for years on Gentoo which has version 115.10.1 as the most recent. I don't send much mail so I'm not exactly sure when this problem occurred, but I'm unable to authenticate with my SMTP server. I have not changed any configuration. Some weeks ago a changed my password on the server, but I made the appropriate changes to Thunderbird password manager. All settings, username and passwords are 100% correct as I copy pasted all of them. IMAP on the same server (uses same credentials) works.

I have tried deleting and re-adding my accounts which did not help. I have also tried deleting my profile folder. All other mail clients (e.g. claws-mail, kmail, mailspring) with the same SMTP server don't have any problems sending mail. This problem seems to only affect Thunderbird and Thunderbird forks such as Betterbird.

I have no firewall and am using SSL authentication with cleartext password on the SMTP server.

I get the following output to console on attempted sending of message:

console.error: (new Error("Server error 503 Service Unavailable", "resource://services-settings/Utils.sys.mjs", 390)) console.error: mailnews.smtp: "Command failed: 535 Incorrect authentication data; currentAction=_actionAUTHComplete" console.error: mailnews.smtp: "Authentication failed: Incorrect authentication data" console.error: mailnews.smtp: "Authentication failed: Incorrect authentication data" console.error: mailnews.send: "Sending failed; Unable to authenticate to Outgoing server (SMTP) mail.kapsi.fi. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'., exitCode=2153066805, originalMsgURI="

Yesterday my Thunderbird was sending but NOT saving sent messages. I was receiving all messages. Today, however, I CANNOT RECEIVE or SEND messages. I have used Thunderbird on this computer for years . . . what has happened?

I would appreciate your help. Win Dawson

how can i stop thunderbird from interacting with windows defender anti virus scan? when ever i download or delete emails i get a few seconds of "not responding " and the whole computer is non responsive. i used to be able to turn off real time scan in security and it would work for a day and then windows would enable it again. now since the last upgrade windows isnt allowing me that option any more. solutions?

About 3-4 days ago, images no longer appeared inline and there isn't a button to show images, just an empty box. My T'bird is set to auto update, so not sure if an update caused this? Not sure if it's related, but at the same time, my rss feeds stopped due to "invalid security certificates." I did not make any changes to previous settings. Thanks for any suggestions!

I am asked to get a new password from my mail server (AOL) every day when trying to send messages. Have to log on to AOL, ask for app password, enter at Thunderbird. DAILY!

Hello, I am trying to send emails from my iCloud account and it always fails due to the SMTP server timing out. I've tried making a new app-specific password, deleting and re-adding the account in Thunderbird, and made sure the authentication settings are right, but it still doesn't work. I can connect to the IMAP server just fine.

I had to delete and add back several accounts due to a change in servers (cox.net to yahoo.com). Prior to this I just had the All Folders, Local Folders and below. Now I have the Unified Folders and below, which are essentially a duplicate of the folders in the old All Folders. (See attached image) Not only is it making things confusing but I'm storing duplicate emails and it seems to be affecting performance, Thunderbird now randomly quits and restarts. So, how do I delete either the All Folders or the Unified Folders and move the few sub folders that are unduplicated into the remaining group?

Every few days, the index pane of some folder gets corrupted. Repair (right-click, Properties, Repair Folder) fixes it. Then a few days later this repeats, with a different folder. I have three IMAP accounts and this occurs on more than one of them.

Any suggestion for finding and fixing the underlying problem?

Since the latest upgrade to 115.10.1 (64-bit) I have an issue about running Thunderbird.

From a clean Windows 11 start up it is OK but then if I then Exit and then try to run the bird again it does not start.

Digging around I discovered using Task Manager, a number of Thunderbird processes run after I had Exited. See attached.

Any thoughts?

emails load very slowly or the app stalls & doesn't respond. Often I have to tap twice to open an email. When deleting an email it can take a couple seconds especially when deleting multiple. I can hit the delete button several time & have to wait several seconds for it to finally catch up. This has been happening for a few months now & is getting worse. Sometimes the pictures in the message load one at a time. It was working right, then one day it started lagging & hasn't been right since.

A while ago, I had to work offline so I had TB download my Gmail account messages. Now I no longer want these messages to be stored locally, because the Thunderbird folder is up to 10Gb, so I unchecked the box in Synchronization for 'Keep messages in all folders for this account on this computer'. I was hoping the TB would subsequently purge the offline folders, but apparently not. Is there a way to clean out the folders without affecting my online Gmail folders as in Inbox and Sent folders?

Here in Jan 2024 suddenly TB will no longer connect to any hotmail or outlook..it says I have to enter a new password but I have not changed my password and can get onto them if I go directly to that site. Any suggestions?

I have tried to restore a backup made with Mozbackup. This was a bad idea. I now have 2 profiles xxxdefault-beta and yyy.default. So I asked Tbird to install from yyy.default where i've got my recent emails and it tried to import without success. I humbly ask for some options. Can I merge 2 profiles ie copy them into one profie folder? Can I hide/rename the profiles then delete Tbird and install anew? I promise on my grandmothers skateboard I will never use Mozbackup again, + . As an aside in appdata,local,tbird,profiles,yyy.default,cache2 there's a whole bunch of alphacoded files. what do these do?

Ta.