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Reguarly with some month between I can´t send email. After many days, which is impossible to use, it is ok without doing anything.

Haven´t manage to send in many days and now it is huge problem.

When I click on send buttom on the email come text about the fail which is 100% wrong.

It say: An error occurred while sending mail. The mail server responded: (then come my email adress): Sender adress rejected: not owned by (the part of my adress in front of @) Please check the message recipient (my email adress) and try again.

This text is 100% wrong because all things is as always! Never changed it. And seeing it in setting it like it should be!

I am almost given up, this come always with months between and that is hopeless.

Please help!

Changing color of the text during composing an email does not work when I use "Choose a color" button. The color in the button changes, but when I click "Ok" the color does not change. The color change works though if: I click "Last-picked color", or when I type color name "Green" or HTML hex, and subsequently click "OK".

How to change the color of text in a composed email when

I am using Thuderbird on macOS.

When trying to run in Safe Mode, and compose a new message, I the Thunderbird stucks, so I cannot confirm in Safe Mode, but I had this issue in the past also on other machines/Thunderbird instances, so maybe someone else had a similar problem, or maybe it is a known issue, already in dev team logs.

Starting Feb 8, 2026 my yahoo accounts no longer work in Thunderbird. I have accessed these for over a dozen years using Thunderbird. In addition, when I open Thunderbird at all I end up getting endless loops of yahoo login messages. The mechanisms in the messages do not work at all. I have received no Yahoo mail since that date. To troubleshoot the issue I tried logging into the accounts directly through Yahoo. Broken, with no access at all to any help resource from Yahoo. Although Yahoo seems to be keeping mum on the problems, there is spotty information online that Yahoo servers were breached a few days ago. One report claimed that user data for about a billion accounts was compromised. I suppose that may explain why my accounts no longer work anywhere- neither from Yahoo itself nor within Thunderbird. Is there a way to disable the incapacitating yahoo popups pending any larger solution to this?

Over the last week I have been experiencing issues that prevent me from using Thunderbird on my computer. It had been working for a few weeks prior, with emails sending without issue. Without any apparent cause, and with the correct credentials set in my account settings, emails are no longer sending. They continue to be received with no issue, and I can move emails into folders etc.., which I immediately see reflected in Webmail. I get the attached error, every time I try to send an email, no matter which address I am trying to contact. I can log in to my account with the same credentials on different software on the same computer, and I have no issues with sending emails from that software, so I can't see how this would be an issue with my computer. I have tried removing the account, and adding it again. The credentials are accepted, but the issue persists. The email also works without any issues via Webmail. I have contacted the hosting company for support, but they have confirmed that this is an issue with Thunderbird. Please can somebody help?

Hello, I just moved my email host from Microsoft to Bluehost and I am having trouble getting Thunderbird set up correctly. I can send and receive from Bluehost webmail, and I can receive in Thunderbird, but not send. I can reply successfully, but all sent mail from Thunderbird shows as sent but never arrives.

I am running Windows 10 and using Thunderbird 140.7.1esr

Any help would be great. Thank you!

John

I have used Thunderbird on my desktop PC for many years, and have now installed it on a Lenovo tablet running Android. The setting up was simple (thank you), and I am receiving emails with no problem. I have tried sending emails and they are simple to type up, but there is no visible "Send" button. I have accidentally sent an email successfully, but have no idea of how this came about. Please help me to send emails, as I am very keen to use the tablet fully. Many thanks, Nigel Olliver.

j'ai ajouté à thunderbird mon compte de messagerie infomaniak . l'intégration s'est faite correctement, mais je ne peux pas envoyer de mail à partir de thunderbird infomaniak sauf si je remplace le serveur sortant mail.infomaniak.com par smtp.gmail.com. quelqu'un sait ce qu'il se passe?

I am using T-bird on a Mac. I set up for a gmail account. I can send emails but do not receive replies, etc. I noticed there is no mail inbox for the account. Settings appear correct. Any thoughts? Thank you.

Hi there

I have a desktop, a laptop, and a cell phone. If I have the application installed on these devices, and setup my email account (POP3 protocol), can I have the application setup such that they are synchronized in any ways?

e.g. if I send an email from the Desktop, will it appear in the Sent folder in other devices? e.g. if I receive an email from the mobile app, will it appear in the Inbox in other devices?

I ask because I do not see that but I do not know if it is a problem with my settings.

Thanks Jason

Have been using Thunderbird on my laptop. Comcsst just changed their email system to yahoo email. I have followed instructions and changed it on my IPhone. When I did that my Thunderbird on my laptop no longer works. What do I need to do? I have used this forum before and know that the responses will be very helpful.and therefore I will express my thanks and appreciation beforehand. Thank you

So, from time to time I need to find a sent email, it is not in my sent folder, I check my settings and there it is, I then set it to use my sent folder on the IMAP server, this works for a while, but then seems the next time I want to find something in the sent folder it has reverted back. Any Thoughts?

Hi, I'm a new user. I cannot send email. Receive is ok.

I get this prompt: Password required for outgoing (SMTP) Server mailhost.zen.co.uk So I add the password, but then I get this error: Login to server mailhost.zen.co.uk with username zen53214 failed. Retry - Enter new password - Cancel I add a new password (the one I use on the zen webmail portal) and I get this message: Sending of the message failed. Unable to authenticate to Outgoing server (SMTP) AUTH command not available at this time. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'. The outgoing server setup is the following: Description: zen53214 Server name: mailhost.zen.co.uk Port: 857 Connection security: STARTTLS Authentication method: Normal Password User name: zen53214

There is a sync issue with zen email password but I cannot change it on the zen portal, because the password in ThunderBird doesn't have a special character and Zen will not let me change the existing password to one that doesn't have a special character.

What can I do to resolve? Please help. I'd like to stay with ThunderBird email.

Thanks!

Mit meinem e-Mail Konto .gmx.de kann ich keine eingegangenen Mails mehr weiterleiten und auch keine neuen Nachrichten mehr versenden. Nach dem Betätigen "Senden" kommt immer der Hinweis "Postausgangsserver SMTP kann nicht authentifiziert werden.Überürüfe Passwort und gewählte Authentifiziermethode unter Kontoeistellungen " .Ich habe aber nichts verändert und weiß nicht was ich in Einstellungen überprüfen soll oder ändern soll.

I have three email accounts all from different sources.

Two of the three accounts work fine but one account will give me this error message. I back up the Thunderbird folder every week and copied the backup to the working folder and I still have the issue.

I've been getting multiple emails of the same in a few folders. I do have a lot of Filters set up for the account affected.