Thunderbird Community Forum

I use a Thunderbird add-on named "Full Address column" on my Windows 11 system. (TBird version 152.0.1, moving soon to 156) It adds a field with the heading: Sender (@) I would like to filter incoming email based on that field. I see that I can edit a filter to customize a Message Header. Should I use Sender (@) or just Sender Or something else ? The use case is rare enough that I thought I'd ask here before experimenting.

I would like to setup Thunderbird as my email client.My email service is provided by Godaddy with an Outlook account. When I am at the incoming server settings, it has my domain name, not smtp.office365.com which I tried with both authentication options (below) and with my domain name, the protocol was IMAP. I changed the port from 143 to 993. I changed security from Autodetect to SSL/TLS. For authentication, there was not an OAuth2 option, I tried Autodetect and Normal password, neither worked. And I used my domain email password. with using my domain name, it came back with an error an suffixed my domain name with :110. It stated that this was not the correct domain and there was a security issue. It is not clear how I should progress.

Thunderbird 152.0.1 Windows 11 Pro 10.0.26200 Build 26200

When I create a new e-mail or reply to one that I have received I am able to type in all fields, but there is no "Send" button to the left of the "From", "To", and "Subject" fields.

I can work around this by clicking "File...Send Now", but that is very inconvenient when I am sending many e-mails.

Hi!

I have configured a EWS email account that requires manual configuration (I need to pass the override Office365 settings with application ID, tenand ID,...). When I select manual config I can configure the EWS server settings OK and the receiving part works OK. The problem is the outgoing server is not created OK (it is imap with password setup). I need to use the same EWS to send the email, imap is not allowed in the account. And I cannot configure the account to use EWS as the outgoing server. The outgoing server cannot be EWS and I need to setup one. So I'm in a loop.

For what I have read, thunderbird can send the email using EWS (https://support.mozilla.org/en-US/kb/thunderbird-and-exchange), but my feeling is that using manual setup (which I need to do to configure this account) breaks something internally and the outgoing is separated from the EWS receiving part. And I cannot configure back to use the internal EWS configuration in the receiving server part.

Can I do something to send emails using the same EWS configuration? What does the automatic setup to use the EWS configuration? Is there any bug for this situation?

Thanks in advance!

Suddenly thunderbird will not accept emails from Yahoo. It use to. The email shows up with a line through it like it has been deleted and the message is blank. How do I fix it? Someone suggested looking at options to see if it's blocked but I cant find the option button

I have been using Thunderbird for years and am on version 152.0.1

I also regularly use the Mail Merge add-on and this has worked great. However, just come to use it and it has put 80 messages into my Outbox but I cannot get them to send!

I hit the "Send Unsent Messages" and nothing happens.

Very frustrating and would be very happy if someone can help identify the problem!

When I press the send icon in The Messaging Company email nothing happens. Therefore I cannot send emails. Have tried various port numbers in the outgoing server and secure connection is established.

Hello. When handling a large volume of emails, some sent messages are not saved in the Sent folder. As a result, they are only saved on the 3rd or 4th attempt, and the recipient receives 3-4 copies of the same email. What could be causing this issue and how can it be resolved? We reinstalled the client and configured it to save sent emails to a different folder, but all without success.

I get a message saying "The certificate is invalid." And I am currently unable to receive emails. When I open the server settings screen, it says "The certificate exception already exists."

Does the Date field in Filters accept relative dates? I get a daily newsletter; I don't want to keep more than one. If I set it to run periodically with Date: set to "today," will it delete any mail older than today?

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.

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.

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.

When I send an email, a window pops up that shows the sending progress. Emails appear to send and save to the sent folder just fine, but the window doesn't close and will remain open until I press the cancel button. Is it possible to fix this?

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.

I have about a dozen accounts with over 50 folders, most with a matching filter. About 100k messages, taking up about 1G of disk space. All but one account is merged under my Inbox to have fewer duplicate In/Draft/Sent boxes eating up window space. I'm using 152.0.1 (aarch64) Release branch on a Mac OS X 26. All are POP accounts on a DreamHost server.

At some point it started to show the draft message on every email, which means on incoming as well. I've had this phenomenon for years.

Recently filtering has started to not automatically run on some emails forcing me to run the filters manually. I've run the repair folder options which does not seem to make any difference.

Since switching to macOS 26 it also does not allow me to move Thunderbird child windows, they simply show up on the default location. But that's for another ticket.