Komunitné fórum Thunderbird

I have Mozilla Thunderbird email application with Windows 11. Recently I have problems opening some email texts, but not all. I do receive the mails and heading, but the contents are not displayed. This goes for some mails, and I do not see any connection as to which ones open and which ones don't. I would appreciate your advise. Bo Dahlberg

Suddenly TB stopped checking mail on time intervals set in the server settings. It does check mail at startup and when manually triggered. MacOs 15.7.3 MacBook pro M1

Hi, I am using Fibrus email (network name is xxx and network key is yyy). Fibrus uses eero as a modem. I cannot work out the correct server settings in Thunderbird as there doesn't seem to be a place for 'network key'.

Most grateful for any help you can give me.

Simon

(Personal info removed by moderator)

COMCAST Outage 2025 12 17

After finally getting my TB installation up and organized (v140.6.0esr), COMCAST/XFINITY just acknowledged that they are having issues with 3rd party email programs. At least with Mozilla Thunderbird. Sheesh!

My ISP, Plusnet, has recently migrated stored email to a new organisation called Greenby. From the day that Greenby confirmed that the migration was complete, no new email has appeared in Thunderbird.

They said that there was nothing to do, although I had to confirm some credentials such as username and password.

Clearly, there was something to do! How can I restart the download of email from my new Greenby webmail account to Thunderbird?

Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) smtp-mail.outlook.com failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again.

Seem to get this (or similar) error frequently. It's like the things I set randomly revert or change. Have sent images of settings. I certainly don't know what to do.

I am using Version 146.0, released December 9, 2025, on a Win 11 Pro, v. 25H2 pc. No problems until today. Messages won't download from two AT&T (ameritech.net) accounts. T-bird is not asking for mail key. No change after restarting T-bird; same result after rebooting pc. How do I restore email access? Thanks.

I use Thunderbird as my email client for my remote machine setup through Parallels Client desktop software for PC. After the recent update, every time I want to send an email, the compose window opens along with another browser window that displays my email account page home screen. Before only the email compose window used to open and after sending the email it would close. Now with the browser window that opens every time, i can't send another email until i close the browser. The attachment that i am including in my email also opens in the same browser window in a new tap and i have to manually close them.

How can i go back to just the email compose window to open and not the browser for every email?

Thanks, Yashar

Hi,

Longtime Thunderbird user. Was online last night, emailing (sending and receiving) perfectly fine. Got online this morning - no changes to my computer or Thunderbird, and suddenly am getting this message:

'Thunderbird could not connect to server inbound.att.net. The connection was refused."

I am able to read mail fine from AT&T Mail via webmail or the Yahoo Mail app. This is strictly an issue with Thunderbird and AT&T.

Any other AT&T users having an issue? Any helpful suggestions? If it matters, I have a bellsouth.net email address.

Thanks!

You seem to have addressed this topic well but not simple enough for complete non-techies like me who can really only do "Click X, then right hand click Y, then click Z" etc. Is there a noddy solution I could try? Thanks. Derek

After getting fed up with the Outlook app on windows. I decided to switch to TB. Now i can recieve my mails but can't send. I don't Use VPN and also checked if Windows Firewall is screwing things up. But those are allowed

Without the following. Unable to login to server (SMTP) smtp.office365.com with username *****@hotmail.com has failed (Translated from dutch)

These are my Settings incoming IMAP server: outlook.office365.com, 993, SSL/TLS, OAuth2 authentication, User Name = *****@hotmail.com outgoing SMTP server: smtp.office365.com, 587, STARTTLS, OAuth2 authentication, User Name = *****@hotmail.com

Optus (Australia) emails can't be sent or received by Thunderbird on my PC via my Optus wifi internet connection. I can use emails on my phone via mobile data with wifi turned off (different email client on the phone, though). Optus checked all the settings on my PC with me and they are all correct. They insist that it is a Thunderbird issue (doubtful, IMHO) and that I contact you. Is there an issue with Thunderbird connecting with Optus email? If so. is there any resolution to the issue? If not, can you confirm no problem from your end so I can get back to them (again!)