Thunderbird Community Forum

thunderbird is not sending or receiving email to a particular legitimate email address; never had this problem in the past--it's just one particular email--please stop blocking it; @inreach. garmin.com

When checking for new email a pop asking for the username and password of the for the email server. Also when a separate email client is downloaded. This only happens when. using a mac book pro. No problem when. using Ubuntu.

Hi. Since the Thunderbird update in March/2026, my Bell sympatico.ca email is no longer able to send emails out through Thunderbird. No error messages but emails never get to destination (I tried sending to myself on both gmail and sympatico accounts). I receive emails without issue. I tested the sympatico from the web or my iPhone and it works. Seems something changed in T-bird back in March?

I validated the Outgoing SMTP server settings and all seems OK (See attached file for screenshot of settings). Any idea why and what changed to cause this?

Tx, Robert Ziwani

突然、どこにもメールの送信ができなくなってしまいました。 受信はできます。 KDDIを使っていますが、問い合わせしましたが、サーバーに問題ありません。 Webメールでは送信できます。 Thunderbird側の問題のようです。 添付のようなメッセージが表示されエラーになってしまいます。 解決策を教えてください。

Suddenly, I can no longer send emails anywhere. I can still receive emails. I use KDDI, and I contacted them, but they said there are no issues with their servers. I can send emails using webmail. It seems to be an issue with Thunderbird. The message shown in the attachment appears, and I get an error. Please let me know how to fix this.

Changed p/w as solution no help Today for some reason Thunderbird won`t download from xfinity. Worked well yesterday,been on phone with xfinity about 1 hr. or so. restart pc no help

Mein Betriebsystem WIN 11 Free-E-Mail bei Telekom Eingegange E-Mails werden auf dem Server von T-Online nicht gespeichert und auf meinem Thunderbird nicht im Ordner Posteingang sondern im Papierkorb vom Lokalen Ordner nicht im Posteingangs. Auf dem Handy werden Sie angezeigt und können gelesen und Bearbeoitet werden. Beim nächsten öffnen der E-Mail App werdenSie gelöscht.

Welche mögliche Ursachen gibt es dafür.

Hello,

Everything working just fine last night. Wake up and Thunderbird will not retrieve emails.

Remembered this old message I got so I went through and deleted my second email address, didn't help.

https://support.mozilla.org/en-US/kb/thunderbird-and-yahoo

Checked all settings compared to Yahoo, still won't download messages. I can even send a message with my current settings no problem, and it does login, just won't retrieve emails. Gives me a connection timeout.

Anyone have any ideas?

Hi there! I cannot get Thunderbird to work with the SMTP-server of my new Outlook account. I checked and double-checked the server specifications, the password, tried OAuth2 as well as login with password. I checked that SMTP is activated in my Outlook settings. Checked Thunderbird and my MacOS for updates as well, of course. I even created a new profile in Thunderbird. The result is still always: "authentification failed". Can someone help? Thanx...

Hello everyone

It's been for a few days since somehow it became unable to send mail. The error message is "The message could not be sent because we were unable to connect to the outgoing (SMTP) server smtp.gmail.com. The server may be unavailable, or the SMTP connection may have been rejected. Please verify that your outgoing (SMTP) server settings are correct and try again. Problem is I cannot see any mistake in my smtp setting. Some help much appreciated. Thank you.

Taka Jimbo

Thunderbird stopped syncing with my GMX email accounts (I have several) a couple of days ago. It keeps reporting that the attempted connection has timed out. I haven't changed any settings on either Thunderbird nor GMX. Any idea why and how to fix it?

I am using version 140.9.0esr-bb20 (64-bit) 

There are three categories of messages I want to filter: 1. Messages where the Subject contains a known word.

   Action: delete  before downloading from POP server

2. Messages from senders not in my address books.

   Action: Move to Junk-folder [and if possible: only download header AND delete them from the server once they have been cleared manually from the junk folder]

3. Everything else

   Action: download the full message to inbox

I'd like to know the settings for __Each message filter __ Check for new messages every 1 minutes __Automatically download new messages __Fetch headers only and anything else that is needed.

I thought I could achieve this out by turning off "Automatically download new messages" and turn on "Fetch headers only". Then, explicitly ask to FETCH FROM SERVER in the filter to get the full messages or "DELETE FROM POP server" as needed. "Check for new messages every 1 minutes" is always on, so I assumed that the filters will be applied every minute. Instead, what I am seeing is that nothing happens, as if "Check for new messages every 1 minutes" does not even work. However, when I do a manual "Get Messages", things seem to work (mostly). If I check "Automatically download new messages" the 1-minute action do occur except everything gets downloaded, regardless of the "DELETE FROM POP server" filters. So it seems I misunderstand these setting. 

Any hints on how to get the requirements done will be appreciated

I recently created a Google Workspace account. There, I have a user profile with a custom email address. I've set up the new account in Thunderbird, and it is working as expected. If I send a message from my "external" account to the workspace account, it arrives, and I'm able to reply back.

One feature of Google Workspace is what they call "alternate email" addresses. They sort of work as an alias for the native address. I have created one such alternate. If I send a message from my external account to the alias, it arrives correctly in the workspace account. However, when I reply from the workspace account, it does not go back to the originating address, but instead it is addressed back to the alias. If I repeat the experiment from the Gmail web interface, it replies to the correct address.

I've downloaded all the headers, and the Return-Path tag is correct. I can provide the full header if needed.

It feels like there is an invisible forwarding action to get from the alias to the workspace account, and that the reply action is incorrectly finding the interim alias. But that doesn't really seem to be what I see in the headers - although I'm probably not the most expert reader of those.

And it isn't necessarily a Thunderbird issue. I can see that there could be something going on with Google. But this is a good place to start...  :-)

Hello, It's getting very frustrating some time hotmail folder/emails are there ans other times not, then some times it will start a downloading all messages folders as if it a new set-up. I have follower all info I can find but it just stays the same.

Kind regards Chris

Although 1900 or more messages are reported, Thunderbird only downloads a few - 18 once, 10 and now only 2 - before stopping. After deleting all messages, stopping and restarting Thunderbird, it then downloads the same few - or less - again, no new ones, and the are very old ones. Screenshot shows current situation - several identical messages only. Version 140.8.1 esr on Windows 11 - both up to date. I don't know what esr means !

My computer has not worked for nine months.

I've been looking at my e-mail on my phone (not in Thunderbird for Android, which pretended to send my messages but didn't). I want it on my computer.

I didn't want to do that right away, but it looks like Thunderbird started doing that automatically when I launched it. It successfully got my small account, of course, but not my big one.

It's been stuck on this for more than 12 hours. (See image. My apologies, I've forgotten how to embed them.)

Is it safe to shut the process down? Whether it is or isn't, what do I do next?

My computer is a MacBook Pro (13-inch, Mid 2012), running OS X.15 (Catalina), with Thunderbird 140.0.1esr (64-bit). The process started before I could upgrade to 149esr.

Thank you for any help you can give me!

UPDATE, 4/11, 8PM EDT: No change. . . .