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I accidently unsubscribed my current calendar. It does not list anymore, I do not know how to list unsubscribed calendars. How to re-subscribe it? (Window 11 w/latest Thunderbird). thanks very much.

I own two computers running MacOS 10.15.7 Catalina and have Thunderbird installed on both. Until rather recently, the Thunderbird version was 140.8.1. Then I noted that it was impossible to send e-mails, and soon discovered that the cause was outdated server settings. They could not handle office365, so I installed Thunderbird 148.01 and changed to settings that should be able to do so. This worked very well on one of the computers, the one which has a fast (SSD) hard drive, but not on the other that has a slow (non-SSD) drive. The error message that I get with the slow computer is, surprisingly, the same as I got with the older Thunderbird. But I suspect that the real cause is some kind of timed-out process.

If any of you could explain what happens and tell me what to do, I would be very happy. Maybe I should choose a Thunderbird version somehere between 140 and 148?

Helge Malmgren

Thunderbird version number: 148.0.1 Mail provider: Yahoo Client OS: Windows 10

The issue and steps I tried to resolve: On 1 Jan 2026 I switched from Outlook client on my Windows 10 PC to Thunderbird 146.0.1. I did not import any user data from Outlook but started with a clean install of TB for the new year. I use yahoo.com with POP3 as my email provider. Server Settings: Server Name "pop.mail.yahoo.com", port 995, SSL/TLS, OAuth2 Outgoing Server: Server Name "smtp.mail.yahoo.com", port 465, SSL/TLS, OAuth2

it all worked fine and I was very happy with the setup. Then from early to mid-February I was unable to use my computer. When I finally accessed Thunderbird again, it connected to Yahoo and showed that approximately 800 email messages would be downloaded and started downloading them. After downloading about 100 messages, Thunderbird timed out and I haven't been able to get it to work since.

I have read and followed or tried to follow these articles plus others that I may have forgotten about (not listed in any particular order) - OAuth2 Authentication for Yahoo, AOL and ATT | Thunderbird Help - including all the steps in Please check the following before asking for support - POP access settings and instructions for Yahoo Mail | Yahoo Help - Automatic Account Configuration | Thunderbird Help - Manual Account Configuration | Thunderbird Help - Thunderbird and Yahoo | Thunderbird Help - Send and receive messages in Thunderbird | Thunderbird Help - Can no longer get emails | Thunderbird Support Forum | Mozilla Support - Emails suddenly stopped downloading to Thunderbird 140.2.1esr | Thunderbird Support Forum - Get Messages | Thunderbird Support Forum | Mozilla Support - Cannot receive messages | Thunderbird Help - Problem with Thunderbird working with Yahoo Mail acccounts. | Thunderbird Support Forum

I have removed all messages from the Yahoo inbox and tried to find one or more messages that may be affecting the download. I don't know the best way to determine that.

I use Windows Defender for my antivirus. I don't see anything in Defender that blocks or scans email messages which would prevent downloads, although I could be wrong about that. if this might be the issue, please provide some guidance about how to check Defender.

I have uninstalled and re-installed Thunderbird. In the process I downloaded the setup file for Thunderbird Setup 148.0 and installed that version. It later auto-updated to 148.0.1. Before installation, I removed all external connections from my Yahoo account and completely removed Thunderbird from my PC, including the profile and profile.ini. When I reinstall and switch the account to POP3, Thunderbird captures the App password from Yahoo and connects just fine. But it still times out while attempting the first download of a message. The first several times it timed out, an error message was displayed but now it doesn't show anything. Except no messages are downloaded.

At this point, I don't know what else to try. Since I don't have much experience with Thunderbird, I don't know how to troubleshoot the process (logs to look at, etc.). I don't want to go back to Outlook but I need the email client to work and download messages. Any help would be much appreciated.

Over the last week or so, I have received an enormous amount of scam, but no matter how many times I "train" the filter, it doesn't work.

I have just received another 3 from this site: mid:02guhjkj6-ABMcSHN6Or-JiC-000000@eu-central-1.amazonses.com, which claim to be from Madasafish Security>security@qi9adgongzenElptrum.de

I have tried on several occasions to follow the manual instructions how to deal with the spam, but I find it so log-winded that my non-techie brain, which is not wired for these kind of things, gets tired and I give up. If anyone has a more intuitive approach how to deal with this, I would be very appreciative. I have marked sites multiple times as spam, but the spam control ignores me!

When I try to send an email, I get the following response. Sending of the message failed. An error occurred while sending mail. The mail server responded: invalid user ID or password. Please verify that your email address is correct in your account settings and try again. Have looked in account settings and cannot see a password anywhere. Email address is correct Help please Carol

I've been a Thunderbird user for years without problem. However, since May 22, three specific messages continually reappear after deleting them from my Inbox.

I keep my Inbox empty and it stays that way, except for these 3 messages. Removing them from the Trash folder has not solved the problem.

My email provider is netaddress.com via POP3 account. I signed on to look at my inbox on their site via a browser, and the messages aren't there.

I have tried repairing and compacting the inbox, but the messages continue t reappear.

Do you have any other suggestions?

TIA.

ChuckM

We are getting substantially more junk mail with the change of our X@RetroCA.com email from Verio/Apollo to roundcube+ - what can be done to get back to very low junk mail like we used to have? Currently I am moving dozens of emails from our inbox to the junk box.

Thanks. John Corgiat for Retrouvaille of Nor Cal X@RetroCA.com

(PII redacted by moderator)

I received a spam message this morning that had a "Disposition-Notification-To" (aka Read Receipt) line that had MY email address on it. I honestly don't know why a spammer would do this - but that's not the issue. I have Read Receipts disabled, but Thunderbird generated an email (to me) and sent it to my mail host. This seems like a bug. Even if the Read Receipt has my email address on it (making it mostly harmless), Thunderbird shouldn't have generated the message. Or am I missing something? Thanks.

Recently...large windows of received emails are showing up in the lower right side...and I have to delete or dismiss. Is there a way to minimize that option and not require me to respond? Formerly it would open as a small alert...and not requiring a response. Just went away, as I recall!!

Whenever I do anything with email I get a message "not responding" which causes a delay for a few minutes before it proceeds This occurs with almost every action Open email, delete email, browse a different folder (eg Inbox to Sent) it suddenly started happening yesterday

I have just been updated to a fibre BT account. My Thunderbird e. mail now refuses to let me send out e. mails, though it receives them correctly. It rejects all recipients. I have checked the outgoing server and the settings are correct. This problem is specific to one computer here, others don't have any problems. Despite refusing to send e. mails, my e.mail service provider, Greenby, has received mail from me this morning which is said to be unsent. What is blocking the server?

It's possible to drag/drop contacts from To to CC or BCC.

It should be possible to do so across messages open in separate windows.

But when I try it, it fails.

Thunderbird will connect to my yahoo server, but will not "bring in" the mail. The msg bar will say for example "loading 1 of 76. The doesn't until server has timed out.

somehow i managed to import from one email account to another thinking i would like it but i don't like since it just makes me have same mail in 2 places but i don't know and can't find how to cancel the import, can someone tell me how