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

I have been using Thunderbird for many many years. I am 70+ and the number and kind of hoops I have to jump through just to keep getting my email are getting beyond me. I recently moved my business hosting, and somehow a change was made in my original email code on Thunderbird so I was not able to do anything with it. I want it on Thunderbird BUT I live in a small rural town and can't find anyone who has been able to help me. The other email systems require a code sent to a cell phone, and although I have a simple emergency phone I do not have a smart phone so I can not receive the code. The other email systems I've tried require an email code be sent to a smart phone almost every day, and although we tried to do this with my daughter's smart phone she is frustrated with me because she has to come over and help me so often. Also, I have so-o-o-o many emails in my original account and I don't want to lose them. Can anyone help??? Does anyone there at Thunderbird work on anything like this? Is there a way to reach Thunderbird directly???

I am trying to add a posteo email account to my thunderbird app on my phone and on my laptop. Each time when I get to inputting my user name and password I get an authentication error.

Hi, We have suddenly stopped receiving emails from our booking provider, 'Inn Style' since the 13th August. All other emails appear to be being received. I have contacted our booking provider and it shows at their end that they are being delivered to us so have suggested it is a problem from the email provider. It is a big problem for us not receiving emails from our booking provider. Thank you for your help, Lucy

My recollection is that prior to a recent automatic update to Thunderbird 140.12.1esr (64-bit) when I had a message composition window open, there were "SEND" button and possibly a "SEND LATER" button (to the left of the addressee and cc addresses in addition to the keyboard shortcuts (CTRL ENTER and CTRL SHIFT ENTER).

Following the update, there is no longer anything to the left of the addressee information. I have checked the toolbar menus, and there do not appear to be any button options. I can still send messages, but the lack of the buttons is a hindrance.

After updating to 153.0.1esr(aarch64). the SEND button has disappeared. There's no way to send an email. (I can receive emails.) I am a Mac mini M2 Pro. OS 26.4.1

I cannot find a link to download a previous release of Thuderbird, which was working fine until this update.

How do I fix this Sending of message failed. An error occurred while sending mail. Th mail server responded Policy -MFRM53 Relay Denied-unauthoruzed. Please verify that your email address is correct in your account settings and try again What should I do

Thunderbird version: 153.0.3 (64-bit), Meadow, release channel, fully up to date.

I can successfully insert my local PNG into a composed HTML email, tick “Attach this image to the message,” and add a hyperlink to the image. The hyperlink works when the email is sent.

The problem occurs when trying to use this permanently as the account signature. HTML signatures I've tried either lose the image, show a broken-image icon, or fail to preserve the clickable image when used automatically.

I have also tested an HTML signature using a local file:///C:/... image reference, which produces a broken-image icon in Thunderbird.

I do not want to host the image remotely. I want the PNG embedded in the HTML/signature and sent with each email.

Can you confirm the correct method specifically for Thunderbird 153.0.3 on Windows, and whether there is a current issue with embedded/Base64 images or clickable image signatures in this version?

Attached is a picture of what my account settings looks like. Thunderbird stopped syncing my emails from a gmail account. How do I get it to continue syncing my emails?

I've never had a problem before but suddenly I'm getting an error when I try to log into one of my accounts telling me "The STAT command did not succeed. Error getting message number and sizes. Mail server pop.gmail.com responded [AUTH] invalid credentials. Why is this happening now?

I have 4 other accounts on Thunderbird and this is the only one that has started giving me problems.

When i attempt to retrieve my email I get the following message at the top of my screen, "The certificate for POP3.pangia.biz expired of 8/13/26. How do I renew it? My email address is jahoagy@signalpeak.net. Thank you John Hoagland.