Thunderbird Community Forum

After returning from a 6 day vacation, my wife attempted to download email from her Yahoo email account. There are nearly 200 messages that have piled up but they aren't moving. I've uninstalled and re-installed TB. I've uninstalled and reinstalled the app password in Yahoo. There is no problem with accessing the email via any web browser. I spent 49 minutes on a tech support call with Yahoo and they have said the problem is with TB because they repeated the same steps I have. I checked firewall settings and the only antivirus program on the computer is Malware Bytes and it's not running in the background. The version of TB is the most recent as of yesterday. I don't see any sketchy looking emails in the web version of Yahoo Mail when it's opened. It's set up as a POP3 account and has been since Cox Internet gave their email over to Yahoo. I'd appreciate any assistance in resolving this because it's currently above my pay grade and tech support at Yahoo.

On my iMac, across all thunderbird email accounts, when I click on "New Message", the new window opens up with the Send button and Encrypt button blanked out. To activate the Send button, I have to right click on the Send button, then click on "Customize..." button, then click on "Restore Default Set". Next new message, same drill. This started one day ago and is a pain in the butt. How do I make the Send button live permanently?

I started a monthly donation to Thunderbird a few hours ago and now I'm thinking it may have been a scam. Not sure, and I have sent an email to your donation email about this. Since I made that donation (and maybe this is a coincidence), I am not able to send any emails. I can compose an email, but there is no "send" button anymore. Can you help me with this? Thank you very much.

Bug report 15 Aug. 2026

The disappearing emails.

It took me a while to find out what was going on. My friend said some of his Sent mail was nowhere to be found. After searching for it in a 'wrong' place it does not exist. Sending to the same recipient and again it just disappears. Simplifying the mail down to just address and the word "test", it still disappears. No combination of a Thunderbird search nor an Everything search finds anything. No return error message from this provider nor the recipients.

This address is for the local electricity board, other mails to other departments

go through correctly and are found in the Sent email directory.

A careful inspection of the contact information shows this is the only department

without a "Shown Name" it only has an email address filled in.

Entering a Name for this contact solves the problem, it now shows up in the Sent

folder and is easily searchable.

I hope this explanation helps some one else with a 'Houdini' email.

hello: for several weeks, each time I tried to add another account back to Thunderbird, MS asked for the verification, and after I added it to link to their server, it kept telling me, "Help us beat the robot," and nothing else happened; the screen stayed blank. I am unable to see any further command. If it is being done using Windows, often you may see holding down the space bar or solving a puzzle to gain access. When it comes to Linux, I ran into this issue.

This is strange! Maybe it is trying to stop me from using this account on this platform to get all my mail here. I've been using it here for many years and no issues. Please see the attached. Please look into this. Thank you....

Cannot send or receive email all of sudden in Thunderbird. When I the click the messages icon, nothing happens, and I get "Could not connect to server mail.twc.com; the connection was refused". When trying to send a m,message I get "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mail.twc.com failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again." No settings were changed and everything was fine when I put the computer to sleep. This happens on both a Win 7 and 11 machine Email is a Time Warner (now Spectrum) Road Runner account (twc.com). Spent an hour with Spectrum, and they say this is a third party (Thunderbird) issue. A friend has the same setup, and is having the same problems that started at the same time. Win 11 version 150.02 Win 7 115.18.0 (latest available for win 7)

Appreciate any help....

My Thunderbird email account no longer lets me send out messages. I get a message error

  QUOTE____

Sending of message failed. An error occurred while sending mail. The mail server has responded. Message contains bare CR and is violating 822.bis section 2.3. Please check the message and try again.

But I am able to receive messages.

Can anyone help. Thanks in advance!!

After system complete reinstallation Ubuntu 24.04 it is not possible to send mails with SMTP Server. Receiving messages is possible!! Two fault Messages happen, I've two SMTP servers: 1. No connection to SMTP possible 2. Server timeout

And yes, I've checked nearly everything what's to find in the internet, reinstallation, change and check settings and passwords, together with the specialist from my provider. Also my provider is not able to find a mistake. As I've found out in the net, there are sometimes problems to connect to SMTP, but no solution found. Is there some security in the UBUNTU system, which blocks the SMTP connection or is this a bug from Thunderbird? Thanks in advance Andreas

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.

Hi David This is the last attempt I did but it failed. Enclosed is the screen shot you have asked for. Keep in mind my WIN 10 has 64 Bit but the last update from Thunderbird was 32 Bit

Heinz

Thunderbird for NixOS nixos - 1.0

I could not figure out how to provide a log at all. If there is a way, please let me know and I will provide one.

Whenever I try to log in with gmail, I get stuck on this dead end:

1. Set up gmail server config (because my email ends in @vcu.edu, however I have tested this with a proper @gmail.com email and observed the exact same behavior)
2. Get propted to login with google, which works
3. Get to the "Mozilla Thunderbird Email wants access to your Google Account" page, select all and hit continue
4. get redirected to `http://localhost:35141/?state=<string of chars>&iss=https://accounts.google.com&code=<another string of chars>&scope=https://mail.google.com/%20https://www.googleapis.com/auth/carddav%20https://www.googleapis.com/auth/calendar` This page does not load, I just get a "unable to connect" error
5. get a notification stating "Authentication failure while connecting to server `imap.gmail.com`
6. get ANOTHER prompt to log in with google, exact same thing happens

please note that the port is random and is different every single time. also, google does not register that I have allowed Thunderbird access to my account, and it prompts me again every single time. Open ports: ``` sudo ss -lntup [sudo] password for jane: Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port Process udp UNCONN 0 0 192.168.122.1:53 0.0.0.0:* users:(("dnsmasq",pid=2224,fd=5)) udp UNCONN 0 0 0.0.0.0%virbr0:67 0.0.0.0:* users:(("dnsmasq",pid=2224,fd=3)) udp UNCONN 0 0 0.0.0.0:33289 0.0.0.0:* users:(("librewolf",pid=185950,fd=164)) udp UNCONN 0 0 0.0.0.0:35410 0.0.0.0:* users:(("librewolf",pid=185950,fd=161)) udp UNCONN 0 0 0.0.0.0:52393 0.0.0.0:* users:(("librewolf",pid=185950,fd=218)) udp UNCONN 0 0 0.0.0.0:21027 0.0.0.0:* users:(("syncthing",pid=1850,fd=19)) udp UNCONN 0 0 0.0.0.0:54112 0.0.0.0:* users:(("syncthing",pid=1850,fd=33)) udp UNCONN 0 0 0.0.0.0:5353 0.0.0.0:* users:(("avahi-daemon",pid=1148,fd=11)) udp UNCONN 0 0 0.0.0.0:41088 0.0.0.0:* users:(("librewolf",pid=185950,fd=169)) udp UNCONN 0 0 0.0.0.0:59247 0.0.0.0:* users:(("librewolf",pid=185950,fd=132)) udp UNCONN 0 0 [::]:44815 [::]:* users:(("syncthing",pid=1850,fd=29)) udp UNCONN 0 0 *:1716 *:* users:((".kdeconnectd-wr",pid=185637,fd=15)) udp UNCONN 0 0 [::]:21027 [::]:* users:(("syncthing",pid=1850,fd=34)) udp UNCONN 0 0 [::]:5353 [::]:* users:(("avahi-daemon",pid=1148,fd=12)) udp UNCONN 0 0 *:22000 *:* users:(("syncthing",pid=1850,fd=15)) tcp LISTEN 0 4096 127.0.0.1:8384 0.0.0.0:* users:(("syncthing",pid=1850,fd=17)) tcp LISTEN 0 32 192.168.122.1:53 0.0.0.0:* users:(("dnsmasq",pid=2224,fd=6)) tcp LISTEN 0 4096 127.0.0.1:8080 0.0.0.0:* users:(("systemd",pid=1,fd=847)) tcp LISTEN 0 4096 127.0.0.1:631 0.0.0.0:* users:(("cupsd",pid=1814,fd=4),("systemd",pid=1,fd=997)) tcp LISTEN 0 50 *:1716 *:* users:((".kdeconnectd-wr",pid=185637,fd=16)) tcp LISTEN 0 4096 [::1]:631 [::]:* users:(("cupsd",pid=1814,fd=8)) tcp LISTEN 0 4096 *:22000 *:* users:(("syncthing",pid=1850,fd=21)) ```

I believe this is all the information i can provide. Firewall was disabled for testing. I cannot log into either my school or personal gmail accounts.

Thunderbird running 70-80% CPU with status bar showing. Once status bar is removed this drops. Have noticed some bug reports mentioned Linux but I'm on Windows 10 ESU (up to date). Updated TB to 153.0.3esr but no improvement. Tried troubleshoot mode but no improvement. Also noticed that emails aren't getting moved to the deleted folder from inbox. Checked today and none had been moved for 3 days. I deleted some of the older ones from 'Deleted' and then it did update.