I-Thunderbird Community Forum

Hello all,

Following some changes in our organization, we had to create new email addresses with new domain names. We have kept the old ones until now but we decided to erase some that had not received emails for a while.

Since we did that, we have encountered some problems regarding one of our computer. We can't send emails because Thunderbird is asking us for the passwords of the deleted email accounts. When we click on cancel, a window opens saying (roughly translated from French): "The email could not be sent. Authentification to the SMTP (outgoing server) failed. Please verify your password and the "Authentification method" in the "Account parameters | Outgoing server (SMTP) menu." The email was sent from a completely different email address than the one linked to the email account.

We deleted the accounts and cannot access this menu. Has it happened to anyone? What would be the solution to be able to send email again on that computer?

Many thanks for all your help, Please ask me if you need anymore information All the best

I've used Thunderbird for years. computer crashed and I'm trying to install Thunderbird on my new PC. Thunderbird cannot find account. I've checked with my provider several times and all settings are correct. Any ideas? I've also downloaded installed and uninstalled 5 times today with the same result.

On Saturday morning 27 June 2026 I tried to login my Orcon email account via Thunderbird (which I have been using for a long time). But my login didn't work, I got a message saying "login to POP3.orcon.net.nz with username habitation failed." On 30th June 2026 I reported the problem to Orcon.

Orcon gave me the following settings for Thunderbird. I have done that and even made a new account: Incoming Server Type: IMAP Mail Server: imap.orcon.net.nz Port: 143 SSL: Off Authentication: On (username and password required)

Outgoing SMTP Server: Mail Server: smtp.orcon.net.nz Port: 25 SSL: Off Authentication: Off

Since then I have spent many hours and going around in circles with Orcon's Technical Support to resolve this, but no luck. They blame Thunderbird. I used Thunderbird Troubleshoot Mode. The message that comes up reads: login to server mail orcon.net.nz with username habitation failed. Please can you check that your server settings above are correct? And if there is a bug? Irma

I have checked the mail setting, they seem to be correct, but this is the message I get when trying to send from any of my email accts.

Sending of the message failed. An error occurred while sending mail. The mail server responded: Email rejected. Please verify that your email address is correct in your account settings and try again.

I use Thunderbird v 140.12.1esr to manage email on my email account frankn413@yahoo.co.uk. For the past 2 days sent emails fail with error message "sending of the message failed. The message could not be sent because connecting to outgoing server SMTP.mail.yahoo.com failed. The server may be unavailable or is refusing SMTP connections. I have not changed my smtp settings - they are Server = smtp.mail.yahoo.com; Port = 465; user name = frankn413@yahoo.co.uk; Authentication method = OAuth2; Conneciton Security = SSL/TLS

Cannot send email on Thunderbird suddenly. This happened after Thunderbird update on 7/16/26 or 7/17/2026. Also could not receive email on Thunderbird for two days after the update but that issue suddenly resolved itself after 2 days . Have tried to change the port but that has not helped. I use rcn.com We could not send or receive there either when I went on the server. Now rcn is working again on the server but cannot send using Thunderbird account.

I find now that Thunderbird requires Earthlink's password each time an email is sent. Earlier it required it once a day. I am on Windows 11 using Earthlink.net for provider.

I can't find the "compose" button that used to be on the "home page" of my Thunderbird email. HELP! It shouldn't be so hard to perform a simple task but something has changed and I can't figure it out.

I get hundreds of emails a day, so setting an alert for incoming mail is not practical. Is there any way to set an alert for specific senders whose emails need to be res[ponded to promptly? I am not at the computer all the time.

I have been using Thunderbird for many years. I just got a new computer and installed Thunderbird onto it. I have several email accounts for personal, business and clubs so this makes it easy to keep track of. I have some gmail accounts and 3 different yahoo accounts. Now when I get an email to one yahoo account it prorogates to the other two. This never happened on the old computer do you have any idea how this happened, and more importantly, how do I stop it?

I have an Thunderbird email account both my wife and I use on phones, tablets and PCs. We use imap on phones and tablets, and pop3 on PCs. Occasionally when downloading the email to the PCs the download stops on a specific email and will go no further. All 3 PCs stop at the same email. IMAP can see the email that haven't downloaded, and if I delete with IMAP the email after the successful downloaded email, the pop3 Clients can download the remaining email on the server. This has happened several times and I don't see anything especially weird about the offending email. Usually some small graphics but no large attachment or anything odd? Any ideas as to what is going on?Version 140.12.1esr

Title: POP3 mail delivering into Archives/Inbox instead of real Inbox — folder appears mis-flagged as special Inbox

Thunderbird version: 152.0.1 (Windows 11)

Problem: After migrating my profile to a new computer (copying the profile folder and profiles.ini, both with relative paths), new mail for a POP3 account (server1, account1) is being delivered into a nested folder "Archives/Inbox" instead of the account's real top-level "Inbox".

Evidence gathered so far: - Real Inbox: mailbox://ABC@savba.savba.sk/Inbox — only 1 message, effectively untouched for weeks - Archives/Inbox: mailbox://ABC@savba.savba.sk/Archives/Inbox — 31,186 messages, 10.9 GB, actively receiving new mail (confirmed with a test send) - Both folders display the same "special Inbox" folder icon in the folder pane - Neither folder can be renamed (rename option greyed out on both) — normally only true special folders are rename-locked - Account Settings shows only 3 legitimate accounts (POP3 savba.sk, IMAP Yahoo, Local Folders) — no hidden/orphaned account pointing at Archives - No message filter is causing this (only active filter is an unrelated SpamAssassin rule) - Identity's archive_folder pref is set to .../Archives (not .../Archives/Inbox), so this isn't the manual-archive-target setting either - Checked prefs.js directly: no mail.server.server1.* pref names an explicit "Inbox" folder path, so the special-folder designation doesn't appear to live in prefs.js - Renamed folderCache.json to force a rebuild — did not fix delivery, and also temporarily broke the Send button in compose windows (fixed by restoring the original file) - Ran "Repair Folder" on Archives/Inbox — only rebuilt the message index (.msf); did not change where new mail is delivered

Current hypothesis: The special-folder (Inbox) flag seems to be stored per-folder (likely inside each folder's own .msf index or an internal DB row) rather than in prefs.js or folderCache.json — which would explain why neither cache rebuild nor folder repair touched it. Two folders under the same account appear to carry this flag simultaneously.

Questions: 1. Where exactly is the special-folder (Inbox) designation stored, if not in prefs.js or folderCache.json? 2. Is there a supported way to clear/reassign this flag from a specific folder via the UI or Config Editor? 3. Could deleting just that one folder's .msf file (Thunderbird closed) force it to regenerate without the incorrect flag, without affecting the 31,186 messages in the mbox file itself? Is this safe?

Happy to provide further logs or additional prefs.js excerpts (redacted) if useful.

Thanks in advance.

When I login into Thunderbird, I continue getting the following error message "Login to server imap.comcast.net with username kfn.appraiser@comcast.net failed". I put in correct password and happens again. Mail server is Comcast. Running Windows 11

I am using Thunderbird 152 on a Windows 11 desktop computer. I want to be able to include a hyperlink in the text of an email message. Please advise. Thank you.

Hello,

I'm currently using the thunderbird client to open a zoho mail account. I've set several filters (around 40) so that incoming emails are automatically redirected to the appropiate folder. If I click on the download/refresh icon (the little cloud with the downwards arrow), new email isn't received. On the bottom, a small message appears ("No new messages on the server" or something like this). You may think that that is precisely because I don't have new emails but if directly go into any of the folders and once again click on the download/refresh icon all of the emails that were supposed to go into that particular folder appear all at once (even mails that are 2 or 3 days old). Now every day I have to go into all of my 40 folders and click on the refresh button.

I look forward to your help. Kind Regards.

Thunderbird is not responding. Xfinity is working just fine I need help resetting is there any way I can speak with a person? I am totally bogged down caring for my partner with dementia. I am able to go to my settings, etc.

I cannot send messages from any of my accounts after migrating to Greenby. I have tried to setup their outgoing server as per their instructions but it does not work. They have a AI tool which I keep going round and round in cycles

After several years of working perfectly,For no reason, I am getting this message when trying to connect to Xfinity email server

"  Login to server mail.Comcast.net with username t_m_f@comcast.net failed."

I have set all Comcast server settings to the default. Going directly to Xfinity email works great . So it must be something wrong with Tbird. I also uninstalled & reinstalled Tbird. This is frustrating !!!!!!