Thunderbird Support Forum

We have recently moved to a new mail server. We currently have about 20 Thunderbird email clients on Windows in an office location and a macOS home machine. On all machines email is configured to use IMAP on hostname.com port 993 SSL/TLS with Normal Password and SMTP on hostname.com port 465 SSL/TLS with Normal Password.

The home machine is working 100% with no issues, it does have a much faster and lower latency internet connection than the office machines.

Many of the office machines are experiencing intermitent SMTP error messages when sending, intermitent, "unable to save mail in the Sent folder of the Inbox", messages and intermitent unable to move messages between folders.

I have checked and double checked the settings on affected machines - however, I believe a settings issue would result in nothing working, not intermitent functionality. Plus all is working fine on the home machine with the same settings (different OS, but ports and security settings all dictated by server).

With one client behaving properly, the server likwise behaving properly when addressed by the working client and the intermitent nature of the problems we are finding, I suspect we have some sort of network issue. Somthing timing out or a firewall/AV software causing a delay.

I have increased mailnews.tcptimeout on affected machines to 250 based on a forum article but this has had no effect (No idea of units here but if it is seconde then I am not supprised - the SMTP errors, when they happen are almost instantanious).

Any ideas on how to trobleshoot this problem further - The problem seems to get worse through the day, although that may just be peoples tollerance of an intermitent issue going down.

Is there a way to stop initial pop ups when opening FireFox? They slow productivity! I don't need to be reminded that I have new emails when I am already in Thunderbird.

I set up a new Windows 11 PC (64-bit) about 2 months ago, and installed Thunderbird Supernova. I allowed MTS to choose all the settings and everything was working fine until about 3 weeks ago I am now running version 115.11.1 (64-bit). I noticed that many messages I recieve at scheduled times every day were not appearing in my MTS message list until sevveral hours (a few actually took 3 days) after their normal delivery times. Checking with the senders revealed no change to the time they were sent. Looking at the messages when they appeared showed that they WERE received on time. Logging into the web interfaces for Gmail and Comcast/XFINITY email revealed that the messages were arriving on time. The only logical conclusion is that MTS has a problem in its IMAP protocol implementation that does not recognize new/unread messages as such, and therefore does not retrieve them. I am legally blind, and up to this point, mTS is the only fully accessible, easy-to-keyboard-navigate email program.

I know this problem has been discussed extensively, but I can't fix it even after reading the previous posts.

I have an institutional email address that uses outlook.office365 server and mandatory two factor autentication. I had my Thunderbird setup with this, which suddenly stopped working one day on my office PC. I updated Thunderbird to the newest version, but the issue pertains. Currently I'm running Thunderbird 115.12.2. on a Windows 10 machine.

When I try to fetch my emails from this server, a popup window appears that asks for my institutional login credentials. When I enter them, a second window appears, asking for the two factor autentication. However, this window seems to be corrupt, as it does not contain any information, and and it's impossible to type in verification code, as there's no input area at all (see the first picture - note that I'm using a localized version of Thunderbird).

When I click on Privacy and cookies in the right bottom corner, then two lines appear (although without any labels), where I can type in my verification code (I guess that it is the second line, because it shows dots in place of the typed characters, as for passwords). A screenshot of this window can be seen in the second picture.

However, after typing the correct code and clicking on the grey button, the first window reappears, this time with my email address that keeps flashing forever and nothing happens. It does not even matter if I type in the right verification number or just anything, it produces the same behaviour. As a result, I can't log in to my mailbox, which is operational, because I can log in there through the web interface of outlook, and also from my laptop using Thunderbird 78.14.0. I also made sure that the server name and authentication methods are correct (outlook.office365.com, port 993, SSL/TLS, OAuth2).

Do you have any suggestion how to solve this issue?

Many thanks.

Updated Thunderbird to 117.12.2 on the 25 June 2024. Since then I am not receiving emails on my computer. I have actually sent some emails but they don't save into the sent folder and I have had a "Add security exception" warning occured when sending.

So problem is not getting new emails since the latest update was loaded. Thanks Neil

All morning I had been receiving and sending emails without issue. Then at approx 12:41 PM EST Thunderbird stopped working. I can send and receive emails through AOL to AOL but they do not show up in Thunderbird. I did not have any other computer issues and did not change any settings. Verizon told me it was an AOL issue, but I was able to successfully send and receive messages with AOL. AOL tried to fix it but ultimately said it was a Thunderbird issue. In the last 6 or 7 weeks I have had issues with Thunderbird. What is going on? Very Very Frustrating!!!

I can send emails but when try to receive emails I get Login to server inbound.att.net with username topgun30@sbcglobal.net failed.

I installed the new version of Thunderbird, and it's strange. I can receive emails and send emails, but I'm getting an error message at the bottom right corner of my screen:

Could not connect to the mail server (and then it names my server name) The connection was refused

What do I gotta do to make this go away?

Ever since the last update of Thunderbird, my Junk and Trash folders are empty. When I mark a message as Junk or throw something in the Trash, the messages simply disappear. I have no way of checking the Junk mailbox for messages that might be there in error. I am also unsure whether my Trash messages are being deleted permanently, or whether they are in a hidden mailbox somewhere. Please help if you can!

I recieved emails from Microsoft to update Authentication to Oauth as support for basic authentication will soon cease. Whilst I have not been experiencing any issues, after following the instructions, also provided here:

https://support.mozilla.org/en-US/kb/microsoft-oauth-authentication-and-thunderbird-202,

I now have an unusable Thunderbird client.

This is because I am having to keep authenticating my outlook accounts (I have about ~100 email accounts). They pop up one after the other for each account.

I believe I went through all the troubleshooting steps but to no joy.

I did notice however, when the "Enter your credentials....." pop up box appears and I go through the motions of authenticating my account and TB against my Microsoft account, the following entry appears under the Settings > Saved Passwords > Saved Logins > "Provider" column for that account:

oauth://login.microsoftonline.com (https://outlook.office.com/IMAP.AccessAsUser.All https://outlook.office.com/POP.AccessAsUser.All https://outlook.office.com/SMTP.Send offline_access)

The credentials include a very long auto generated password starting similar to "M.C533_BAY.0.U.-........"

A couple of things to note now regarding the oauth entry:

1. It possibly does not always get created when re-authenticating 2. After quitting TB and then re-launching TB, it dissapears

So the solution would be to somehow ensure this entry is created and it sticks even after quitting TB, since for those accounts that include this I do not have get the "Enter your credentials....." pop up box.

Is this something TB can investigate?

I posted this the other day and have had no reply or I maybe cannot find the thread. Please help.

I cannot send messages from Thunderbird since it was last updated on my pc. Version 115.12.2 (32 bit). I have checked the server settings and they have not changed in years. I have been in touch with Virgin Media, my service provider, and I can send emails when logged on to my account and not involving Thunderbird. I can also send emails from my mobile phone using Gmail. The issue would seem to be with Thunderbird and this recent update. Please point me in the right direction, bearing in mind I am not particularly computer literate.

After Thunderbird update 115.12.2(20240621154414) was installed on my PC on the 25/6/2024 I am unable to receive emails. I continue to get an error message on account noeljc@optusnet.com.au (IMAP)

   Connection to server mail.optusnet.com.au timed out.

or Failed to connect to server mail.optusnet.com.au. I have looked thru all the forums and tried various solutions without success including extending the setting for mailnews.tcptimeout to 3000. I have checked and validated my account server settings are as recommended by my ISP(Optus) are correct for authenticated emails. I even turned off my Norton VPN completely to no avail even though I use Split tunnelling to allow Thunderbird thru it as an exclusion. It appears to me there maybe a bug in the last Thunderbird update causing this. I have had this issue in the past at various times intermittently but it has always seemed to correct itself. I have been in contact with my ISP(Optus) regarding this error and all they could say was to logon to email server via webmail and did not offer any other solution. It appears there is a communication breakdown between my PC and the Email server somewhere. As I stated this only happened after the last Thunderbird update on my PC on 25/6 as it was working up until 24/6. I also have another optus email account for my wife on Thunderbird which has the same error messages. Could the Mozilla gurus please advise what to do.

First I got problem.with my laptop. I went to a service shop, but the technician caused me to loose the old files of my e mails. I seriously need help to get my old e mails accessible

Good morning. I have been unable to receive e-mails since 30/05/2024. Has the fact that I received an e-mail message from "Mail@voice" <mboudreaux@firmgroupagency.com> on 31/05/2024, got to do with the problem. I would be grateful could help solve the problem. Thank you. Emyr Davies.

It has stopped working. Starting 2 weeks ago, Thunderbird keeps saying "Login to server imap.aol.com with username stuart_jones@verizon.net failed." I don't know what to do.

My Local Inbox suddenly started to arrange itself by group according to correspondent. I can't get the emails back into chronological order. I can't work with a mail program that doesn't give me my messages in chronological order, with most recent at the bottom. If I did something to cause this change, please tell me how to undo it. I have about eight email addresses, and they all feed mail into the Local Inbox.

On the top of the left side of the incoming email page, next to my email address, I would like the following alternatives to appear: answer, answer all, forward . . . I have had them before, have never had a problem with them, but I must have pressed the wrong key as now I get the following instead: an icon with a pin-up button, a phrase about filtering, and then five icons with an envelope, a star, a notebook . . . What do I need to do to recover the original layout?

This new version of Thunderbird (115.12.2) is not the best. The Composition toolbar doesn't exist when typing a new message and I no longer have a menu bar when typing a new message.

Another issue is on replying why do these sideways "V's" show at the beginning of each line of the senders email when replying. Sometimes it will be just a black line all the way down. When I saw those I felt like I had woken up in 1995.

I am using Windows 11 Pro.

Thank you