Forum der Gemeinschaft Thunderbird

I recently updated the computers at my shop. My shop uses an older program Mitchell 1 to process and organize invoices. I have used Thunderbird to email invoice pdfs for the longest time but now after updating I get “ERROR SENDING EMAIL. MAPI RETURNED -2147467259” it’s my understanding MAPI is outdated but I figured Thunderbird would still support this function.

On January 1 my desktop version stopped downloading my GMAIL but my other non gmail are still downloading

I use Windows 10 and the version of Thunderbird is 147.0 64 bit

What can I do to fix this?

I quite often get this message, though it tends not to be a problem later "Unable to write the email to the mailbox. Make sure the file system allows you write privileges, and you have enough disk space to copy the mailbox"

One of the solutions seems to be Compact a File. How do I do this?

Filters *unreliably* sort the mail into their target files. I have reconstructed the filters from scratch twice, both times with identical, unpredictable results: each filter works properly on the inbox when tested, but each filter only works *sometimes* in the normal course of getting (IMAP) and sorting mail. When getting a batch of mail, some messages are sorted, while others are not. When testing the same filters on the same (still unsorted but already picked up) messages, those same messages are recognized and sorted correctly. The question is: Why are the filters not working reliably during message pickup?

The mail server is running "Debian stable" Dovecot. It seems to work well; I'm not *missing* any messages, but they're not always getting into the right folders. Instead, some messages, and sometimes quite a few messages, may remain in the inbox. I surmise that the problem is in Thunderbird, where somehow the downloading process somehow undermines the sorting process. A queuing issue? A communications-with-Dovecot issue? (The server is in Paris and I'm in North America, but there doesn't seem to be any undue latency that I can detect. The server is not very busy, that's for sure.)

In case it helps: I filter mostly on `DKIM-Signature`, `Authentication-Results`, and `Received` header entries. In a couple of cases, I use `Body`. I'm almost always using "match any" (as opposed to "match all").

Hi there! I and my colleague encounter some bugs with Thunderbird and we would like to seek your advice in regards of the issue.

1. <user a@citizen-systems.com.hk> was supposed to get a cc copy of the email sent by <user b@citizen-systems.com.hk> at Mon, 12 Jan 2026 09:35:19 +0800 but it never reached. The receivers, namely <user c@systems.citizen.co.jp> and <user d@citizen-systems.com.hk>, however, were able to get the mail. <user d@citizen-systems.com.hk> and <user a@citizen-systems.com.hk> are working at the same office and under the same network. Network provider checked the protocol, router, traffic and firewall are working as normal.

2. <user e@citizen-systems.com.hk> found a number of emails that she kept at "Inbox" disappeared on 12 Jan 2026 morning +0800.

She is unable to find it anywhere at her whole mailbox but has to ask the senders to resend them to her.

It would be very much appreciated if you can check and advise how to prevent the issue from happening again.

(PII redacted by moderator)

I have a windows 11 pc with thunderbird 147 installed. It worked until Jan 16th, 2026. I added the account to my Linux pc that has thunderbird 140.5 ESR inststalled and it works fine with the account from the windows 11 pc.

We have Thunderbird installed on 2 computers and, for the last 3 days, we have been to receive, but not send email. We can log in to our email provider online and send from there with no problem, so it's strictly a Thunderbird issue. We use Graceba/WoW for our email/internet, windows firewall, PC Matic AntiVirus, Windows 11, and Thunderbird version 147.0 (this information is the same for both computers). When we try to send an email with Thunderbird, the following error message pops up: "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) smtp.graceba.net failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again." Our outgoing server settings are correct; nothing has changed and no updates have been done. Something happened over the course of a day 3 days ago (it was fine in the morning and not fine in the afternoon) that caused us to not be able to send email. Please help!

I transferred to a new Apple Mac Book Pro in Nov 2025. Downloaded and Installed thunderbird version 144.0.01. No problems. Did updates and started to encounter issue with sending mail. Last updated version was 147.0. Had to go back to version 144 to get a properly working Thunderbird.

Is there a bug with version 147 for Apple Mac Sequoia that means you cannot send more than one email at a time from pop3 accounts? I send an email, and then have to quit Thunderbird and re-open if I want to send another email. I have done a lot of testing and checking over the last few weeks to try and get Thunderbird to work properly, but nothing worked. Plus a date edit bug / feature for tasks?

I have several accounts, all pop3 apart from 1 Gmail account. No matter which account I start from, if I want to send subsequent emails from a pop3 account, I have to quite Thunderbird. No matter how long I wait to send the email. I tried saving the email as draft, and send later. Does not work. I did not make a note, but I think in my testing I may have been able to send more than one GMAIL email - it is IMAP. I know I did send 1 email from my gmail account, and then tried one of the pop3, but was not successful. At all times fetching mail has not been a problem.

I did all the standard checks which did not make any difference: the server settings; addons disabled; virus checker disabled. Removed an account and re-added; deleted SMTP server settings and re-added. Proxy settings; and so on.

On my old mac running version 128.14 no problems at all. I compared settings. Could not see any differences.

On the new mac, created a new user, and new thunderbird profile. Added 1 pop3 account only. The problem was exactly the same. So it was not a profile issue.

Decided to revert back to older version 144. PLEASE could Mozilla add a facility to Thunderbird to allow you to use existing profile rather than going through the operating system to get it to use my existing profile. I did get the old 144 version to use my 147 profile. After testing yesterday and today it all appears ok. I can send more than email at a time both from the same account, and from different accounts. What I do notice is it does seem to be slow on making the connection on some accounts. Most of the accounts are from the same host but the connection speed for sending is variable across the accounts from the same provider. My email is purely the words testing and testing in the body so not large. Is that to do with the space I have assigned to email mailbox at the provider side?

One other issue with 147, and do not know if it is connected or a new feature of 147 and that is not being able to directly amend dates in tasks? In the newer versions of Thunderbird I found that I can only amend the date of a task by using a popup calendar and choose the date. In version 144 I can now amend the date of tasks by typing in the date field. Is it a feature / setting of 147 or a bug?

My question / subject tells most of the problem. Here it is again in slightly more detail: SPF fail is the part of the undeliverable response to two different emails sent yesterday. What to do? Is down to me or ISP? Is this a Thunderbird problem, or a server level issue? If it is Thunderbird, what action do you suggest?

Hello, I am using TB 140.7.0esr. I have five email accounts in TB and all send emails but one. This one email receives IMAP emails, but will not send. All emails accounts are hosted on Godaddy Office 365. The one I am having issues keeps popping up the dialog box to enter password when sending. When I click on the button to add a new passoword, TB just tries sending again. It never shows the popup to enter the new password. I have deleted this account and installed new, still same issue, only on this one email acount.

Thank you, JR