Thunderbird Community Forum

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.

Thunderbird--All of my current year INBOX emails disappeared. I have tried repairing the folder, deleting INBOX.msf and restarting including in troubleshooting mode, reinstalled Thunderbird. None of these actions changed the situation. Is it possible to retrieve these messages?

The INBOX folder is much larger than the INBOX.msf folder, so I'm thinking the message info is in there?

I;m using Windows 10.

Today I have experienced a problem downloading new messages, bulk, trash or anything else in my mail server into thunderbird. it requires my primary password and then my regular password. I just set up my primary password so I understand why it is asking for that, but I don't understand why it is also asking for my regular password before I can get access to the mail server that I am using. the regular password was set up on 6/17/24 and until today it was working fine.

I just wonder why all mails suddenly seem to be totally disappeared. Without any warning. Althoug there should be 20 mails (which figure has only been creasing for the time being/already for hours. :( Also all ready models/musters seem to be deleted. So I can't add my usual signature as easy as usuaylly:

Heli Mäki [edited] FINLAND tel. [edited] < [edited] @gmail.com>

/edited address, email and phone# from public community support forum

Hi

When Thunderbird is started maximized it overlap taskbar if is set to hide and taskbar won't show until Thunderbird is minimized and maximized. Another way is to press the Win key two times. Then the hided taskbar can be shown/use. The same thing happens to Firefox. Only when is first started. Then if Firefox is minimized and maximized, press Win key two times, press F11 two times then the hided taskbar show/hide normal.

It is a setting that can be changed to start Thunderbird and Firefox in full screen and do not overlap hided taskbar?

I've tried setting up Thunderbird archiving according to the documentation to save archived messages locally, and in the same hierarchy they had when I archived them. That is, if I have:

INBOX

   Box1
   Box2

... etc. then archiving would create a parallel structure in Local Folders

However, this isn't working.

I select "Keep message archives in Other (Archives on Local Folders).

For "Archive Options" I select "A single folder", "Keep existing folder structure of archived messages" and "Recreate inbox folder".

However, when I archive something, Thunderbird just creates a folder "2026" (this year) and puts the message in there.

Why are my settings NOT working?

- Tim

I like to default to having threading on. It used to be that when I opened my Inbox, every email thread was closed/collapsed. Now they're open (started somewhat recently).

I can get numerous separate emails where each one can generate lots of responses, meaning they threads get long, sometimes within a few minutes or hours. Having them closed by default (rather than open or unthreaded) makes it to see each individual email chain and other interspersed single emails.

I tried google searching; also tried threaded and grouped by sort (with the default sort set to thread), and it doesn't seem to help. Any help would be appreciated!

Hi all — I’m running into a persistent threading issue in Thunderbird (v.148) vthat survives profile rebuilds and affects only specific conversations.

Symptoms Some threads show the expand/collapse carrot normally.

Other threads (same accounts, same folders, same time period) do not show the carrot.

The pattern is consistent: the same conversations fail before and after a full profile rebuild.

Both Inbox and Sent show a mix of threaded and unthreaded conversations.

No global setting seems to be wrong, because most threads work correctly.

What I’ve already checked mail.strict_threading = false

mail.thread_without_re = true

View → Sort By → Threaded

View → Threads → All

Folder Repair on Inbox and Sent

Full profile rebuild

Re‑added all accounts

Rebuilt .msf files

Verified that threading works across folders (Inbox ↔ Sent)

Verified that threading works across accounts

Verified that threading works for most conversations

Header checks For the conversations that do thread, headers look normal.

For the conversations that don’t thread, the headers also appear normal:

Message-ID: present

In-Reply-To: present

References: present

No obvious corruption, malformed IDs, or missing brackets.

What I’m trying to understand Why would Thunderbird:

Successfully thread most conversations

Fail to thread specific conversations

Preserve the same failures before and after a rebuild

Show carrots in Inbox but not in Sent for the same conversation

Show no global misconfiguration

Is there a known edge case where Thunderbird rejects a thread even when the headers appear correct?

Are there hidden rules about ambiguous References: chains, multi‑server storage, or cross‑account BCC workflows that could cause this?

Any insight into how Thunderbird decides not to show a carrot would be appreciated.

Thanks in advance.

Since the 26th of Feb. my thunderbird stopped downloading emails from any of my GMail accounts. I've accessed the email and i have a bunch of new emails there but for some reason they are not transferred to thunderbird anymore. I'm think i've installed a new thunderbird version around that time but im not really sure if that was the cause.

Also, no error message appears. it just says no new emails.

Already cleared the login details and logged again, still same issue. I'm using pop connection.

today, when I clicked on the Thunderbird icon (on my desktop PC), instead of my usual window popping up, an odd looking window came up instead that asked to sign into my account using my username, email address or mobile number. But when I tried (several times), none of them were recognised and now I can't access any of my emails because now when I try I get a message that says "Edge: Too many requests" ... this is followed by a pop-up window (bottom right), that says, "Authentication Failure while connecting to server imap.aol.com. This in turn is followed by another Crash Report window (attached screenshot).

I tried uninstalling Thunderbird, deleting cookies, etc, then reinstalling ... but no change.