Thunderbird Community Forum

Since about November 2025, all the mails I try to sent to @sfr.fr addresses (different recipients) fail and I get the following message: Sending of the message failed. An error occurred while sending mail. The mail server responded: <xxx.xxxx@sfr.fr> recipient domain rejected (blacklisted by local policy).

Please check the message recipient "xxx.xxxx@sfr.fr" and try again

I did not have this problem before. If I use Greenby's web mail (My email provider ), the messages are sent without any problem. I would very much appreciate some help to solve this problem! P.Y: pemy@pemyoung.plus.com

My Mac last night lost thunderbird (and numerous others things) and it's setting itself up again. I get an error that smpt already exists and I can't go any further! What's going on? Using Comcast Mail.

I have upgraded to TB153.0.3ESR. I've been on the ESR stream for a long time now. But recently, I started having trouble with my google calendar appearing. I've deleted the provider plugin, I've moved to OAuth2, and for the most part, calendars that I have that are read-only from google show up all the time. But my personal read/write google calendar will not show up.

If I go in and delete the cache.sqlite file, and then start Thunderbird, my entries show up. However, if I switch to a different week, my read-only calendars still show up, but my personal calendar goes away.

I've tried everything listed in all of the steps to fix this, but I can't find anything that gives a clue as to what is happening. Anyone else see this?

Steve.

Hello. I have been unable to send email from one of several POP accounts on Thunderbird (v 115.18.0). I believe this occurred after Network Solutions changed the SMTP server for that email account. I am able to send email from my Gmail IMAP account setup on the same Thunderbird program on my PC. I have tried all the port and authentication settings for SLS/TLS and STARTTLS, changed/updated passwords, etc. I do not get any error messages, just never receive the test email I send to my other accounts. I updated the SMTP server on my iPhone mail app to the new NetSol SMTP and it works on that platform. I just cannot get it to work on Thunderbird on my PC. NetSol support said to delete account and start over which is not possible as it is my business email account. Also, the inbox is too large to back-up to an external drive. Any suggestions? Thanks in advance. John

Bonjour, Je vous promets que je vous fais un don dès que vous aurez mis fin à votre publicité mensongère à propos des Dossier récents : ils ne sont jamais triés par ordre alphabétique, quelque soit le paramétrage demandé.

I have followed the instructions that several people give to transfer my existing Thunderbird installation to a new computer where I have just installed Thunderbird. That is I copied the Thunderbird folder and put it in the Roaming folded found in %appdata%. Both computers are on Windows 11. When I open the new Thunderbird, it does not recognise it. Furthermore, in Help>Troubleshooting information>Profile folder when I click to open the folder, it looks for a folder that is not in my previous Thunderbird installation: qr19mupe.default-release instead of the one that came with my imported Thunderbird folder. Has this happened to anybody and found the solution? Can anybody help please?

Hi, I have 2 Local Folders and an additional Local Folders1 folder. I need tol remove two of them so my Msg Filters work properly. Do I need to edit an additional file inn my Proffile folder? Need some guidance please. Am I not following rules and guidelines? Thanks

Disabled in a nursing home.

I can receive but not send messages, this has been going on for over a month now. I've tried several times to fix this but unable to correct it. The first error message prompted me to check password which I did. It worked for a few days, then it didn't. Checked with my IP to make sure I have the right port number and security settings: Port: 587, SSL/TLS. Started getting other error messages... this one is the latest: The message could not be sent because the connection to Outgoing server (SMTP) smtp.comcast.net was lost in the middle of the transaction. Try Again).

I'm on Macbook Air (Sierra 10.12.6). Using Thunderbird (115.18.0 (64-bit), says it's up to date. I've attached the last two messages and a snap shot of my smpt settings. My brain is fried from trying to figure this. I'm also wondering, if my OS software no longer supports this version. Any help would be greatly appreciated.

Some time ago I went tinto exceptions and put in some unwanted email addys and they were blocked. I am getting unwanted emails tried the same thing, but they are still coming through. Here are some of the emails; contact@news.comoundeesgtream.com contact@news.musteraliteinfo.com

Can you tell me how to block these from showing up in my email account? John @ thdtgog1118@outlook.com

Hello. I need to reduce size of my email folders - specifically gmail. I am trying to delete a large series of attachments, while keeping the original email. SOMETIMES this works, but sometimes it does not, and then I am stuck! Any ideas? THanks.

Hi, Need help with maps that cannot be removed. Thunderbird downloaded my map configuration, after a new Thunderbird installation, from my online account/my internet provider which was OK. After that I removed all maps on my online account but the maps in Thunderbird is still there but out grayed and I cannot delete them?

I uninstalled Thunderbird and also removed Thunderbird associated maps under %AppData% and %LocalAppData% but when I do a new clean installation same maps shows up in Thunderbird again? I waited some days and did a new installation again, but same issue. I have also deleted everything in W11 cash memory.

Attached picture shows the out grayed "NyMapp and subfolders" I cannot delete. How do I get rid of those folders?

Any help is appreciated.

Thank you for the advice on copying the Thunderbird folder, which I have done. However, what is failing is the adding of further existing email accounts. I enter the Account name, the email address and the password but I still get Authentication error. I have, after some difficulty, succeeded in adding five accounts with three different hosts. The further accounts I wish to add use two of the hosts of the successful additions.

Hello Folks,

We are a team of around 15 users who have been using Mozilla Thunderbird with Google IMAP for the last few years. Until recently, Thunderbird has been working reliably without any major issues.

However, for approximately the last one week, we have been facing a serious performance issue with incoming emails. Around 12 out of 15 users are experiencing the same problem.

The main issues we are facing are:

Newly received emails take a very long time to download. After clicking on a newly received email, it takes a considerable amount of time to open and display the content. Emails appear to be downloading extremely slowly, even though our internet connection is a 100 Mbps ILL (Internet Leased Line). The issue is affecting multiple users simultaneously, so it does not appear to be limited to a particular user's Thunderbird profile or PC. We have already tried Repair Folder / Repair Inbox, but the issue persists. We are using Google's IMAP servers for our email accounts.

We are currently using Mozilla Thunderbird 153.0.3 (64-bit) – Meadow Badge.

Could this be a known issue or bug in the latest Thunderbird 153.0.3 update, particularly with Google IMAP?

We would appreciate any guidance from the Thunderbird community/support team on how to troubleshoot and resolve this issue. If there are any recommended settings, logs, diagnostics, or Thunderbird configuration changes that we should check, please let us know.

Since this issue is affecting 12 out of 15 users, it is becoming a significant operational problem for our team.

Any help or suggestions would be highly appreciated.

Thank you.

Hello Folks, We are a team of 15ppl using thunderbird from last few year and it work flolessly in these years but from last 1week i have been facing a serious issue of : INCOMING EMAILS TAKING A LOT OF TIME TO OPEN AND READ, fresh email when received and after clicking it takes a lot of time of open, having a 100mpbs ILL speed, out of 15 / 12 ppl are facing same issue, even after repairing the inbox the issue remains same, mails are getting downloaded very slowly...we are using google imap server for the same, need help to resolve the same...is it the bug in the latest update 153.0.3 (64-bit) Meadow badge

メールソフトをアウトルックからサンダーバードへ移行したく、サンダーバードのアプリはダウンロードしましたが、 サインインに失敗なのか？認証できなく困っています。受信サーバーはIMAPですが、サンダーバード ではPOP3とでてきたので、手動でIMAPにかえてもみましたが、とにかく認証しないのです。 どうしたらよいか教えていただきたいです。

I have a new PC. I have added five email accounts, three different hosts, with some difficulty. Thunderbird finds the details for others but then refuses with the message Authentication error. Unable to log in at server. Probably wrong configuration, username or password.

I added Thunderbird by copying from my old PC. The hosts for those not yet added are the same as those added.