Thunderbird Community Forum

TB is not downloading pop3 emails again.

What does this mean?

NetworkTimeoutError: a Network error occurred Pop3Client.sys.mjs:380:18 SecurityError info: Pop3Client.sys.mjs:440:20 SecurityError cert chain: legacy.pop.mail.yahoo.com; serial# 07:CF:5F:D8:B7:96:17:C0:9F:C0:58:12:90:5A:41:8F <- DigiCert Global G2 TLS RSA SHA256 2020 CA1; serial# 0C:F5:BD:06:2B:56:02:F4:7A:B8:50:2C:23:CC:F0:66 <- DigiCert Global Root G2; serial# 03:3A:F1:E6:A7:11:A9:A0:BB:28:64:B1:1D:09:FA:E5 Pop3Client.sys.mjs:445:22

I've been having a bit of a nightmare - I was using Google mail - then I migrated to Proton - now I am going back to Google (for now).

I added my email address to Thunderbird and then had to installed Proton Mail Bridge to allow me to download all those emails to Thunderbird. This is apparently 9.5GB worth of email according to Mail Bridge.

Now when I open Thunderbird it keeps crashing, becoming unresponsive. I don't know how to proceed - do I need to sign out of Proton Mail Bridge - or Delete my account in Mail Bridge - or something else.

I can't tell if Thunderbird is busy "compacting folders" or some other task...

I have been in the meantime trying to delete messages from my Proton mail (in my browser) to see if that helps. But I can't tell if this is doing anything beneficial or not.

I literally can't open Thunderbird now without it crashing, despite me not taking any kind of action (just the spinning/loading wheel constantly visible).

Hope this is enough info but happy to share anything else! I have tried restarting the computer too.

Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mail.twc.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.

I have installed Thunderbird on my MacBook Air (Tahoe 26.4) and synced all my hotmail emails from an account which I wish to delete. Do I need to do anything before deleting the account i.e. will they stay in Thunderbird or is there a setting I need to change first?

Our time zone (Vancouver, Canada) did not revert to Pacific Standard Time. We remained on Pacific Daylight Time. I changed the time on the computer system. However, when I receive emails in Thunderbird, it shows a time of one hour behind (PST) and not the correct time (PDT).

(Webmail does show the correct time.)

How can I change Thunderbird email to the correct time?

I am trying to add an Proton mail account to Thunderbird using the Proton Mail Bridge (PMB). In the PMB guide it is recommended to uncheck Account Hub in the Setting>General. The problem is that the Account Hub still pops up when trying to add a new mail account - it simply refuses to go away regardless of several restarts of both the computer and the mail client!

A timeout in the connection to the server means that I can neither receive nor send emails, even though this had been working until today. I'm working on the latest windows version. How to solve this problem?

Hello, I'm currently having a problem with Thunderbird version 15.9. I can no longer sign in to my Google-Account after I set new passwords and entered them in Thunderbird. Several attempts were unsuccessful. I then deleted all entries related to my Google account. Adding the existing account again failed. I received two error messages. Error message 1: “Waiting for authorization during sign-in". Error message 2: “The inbox server is already in use.” An other E-Mail Account runs perfect. I urgently need help.

Hi everyone,

Why is it not possible in Mozilla Thunderbird to compose a new message within a standard tab in the main window?

Or is Thunderbird designed in such a way that the compose window always opens in a separate, standalone window? There is currently no option within the program's settings to change this behavior to use a tab instead.

Thanks!

The past couple of months, sending emails has been difficult. I did all the troubleshooting, such as verifying the network settings, allowing a longer time for connecting, tweaking Avast settings, rebooted the Spectrum modem, etc. It doesn't seem to matter if the email is only text or if it contains graphics or attachments. I have 6 Roadrunner accounts in Thunderbird, and the problem is with all of them. I have automatic updates turned on. Sometimes it takes several tries to get the email sent. Thunderbird is sending some of the "not sent" emails to a local folder, which is hard to get them out of. What am I missing? tnx

I use HTML as my signature. It has been working just find, but lately when people reply to me, their messages were coming in blue text. So today I changed the: Settings > General > Plain Text Messages > Quoted text formatting from blue colour to black (I have no idea how that was set to blue in the first place). that is all I did. Image attached of the change I made.

In any case, after that, when I tried to send a new email my HTML signature no longer displays the correct font (Pristina) but shows only variable text. The HTML file is not corrupt, it still looks fine in the actual file I saved, but, Thunderbird is changing it somehow. Even when I look back at sent files, Thunderbird is showing me the variable text and not Pristina.

Any assistance would be much appreciated. With thanks, NM

dal mio account tizianomorselli@gmail.com sono scomparse le email inviate e ricevute dal 23/04/26 al 23/10/26. Non sono nel cestino non sono nello spam e non sono nell'archivio.

Emails sent and received between 26/04/23 and 26/10/23 have disappeared from my account, tizianomorselli@gmail.com. They are not in the trash, not in the spam folder, and not in the archive.

I need assistance with a persistent Microsoft 365 authentication problem in Thunderbird on Windows 11.

My business email is hosted through GoDaddy's Microsoft 365 service. Thunderbird repeatedly fails when attempting to send messages, displaying:

"Login to server smtp.office365.com with username [business email address] failed."

We have attempted to troubleshoot this problem on several occasions without achieving a reliable solution.

Previous troubleshooting has included checking SMTP settings, STARTTLS, OAuth2 authentication and investigating Microsoft Graph integration.

Our earlier investigation also indicated that SMTP AUTH may be disabled for the Microsoft 365 account.

The mailbox works through Microsoft Outlook, but having to remember to use Outlook separately creates a risk of missing time-sensitive business correspondence.

I would particularly appreciate assistance with the following:

1. Establishing a reliable, supported connection between Thunderbird and my GoDaddy-managed Microsoft 365 mailbox. 2. Determining whether Microsoft Graph integration can resolve this without enabling legacy SMTP authentication. 3. Identifying any known compatibility issues involving GoDaddy-managed Microsoft 365 accounts. 4. Providing specific diagnostic instructions so we can establish why authentication is failing rather than repeating unsuccessful configuration changes.

I can provide screenshots, Thunderbird version information and diagnostic logs with sensitive information removed.

I would be grateful for detailed technical guidance because repeated attempts to resolve this issue have been unsuccessful.

I have a number of calendars subscribed in Thunderbird, some external ones along with my own one, One is an Awareness Days one. That is one I like to glance at daily, but at midnight GMT/UCT the blasted thing causes a whole series of notifications to pop up, one after another, one for each awareness day the following day is - and some days that's quite a few. It's incredibly annoying when I'm in the middle of something and am interrupted by the notifications. i want the calendar for me to glance at when i want to; I do NOT want the notifications from this calendar, but do for e.g. my personal calendar so can't globally turn off all TB notifications,

I have:

1 in calendar tab, in the list of calendars clicked on the mute icon so it's showing a bell with a line through it and says it is muted on mouseover.

2 In its properties> Edit Calendar, unticked Show Reminders, have nothing under the Add notifications.

3 Following a suggestion from the Google AI, changed TB to use its own notification display rather then the Windows 11 one.

But no effect: every midnight I get the damned parade of notifications getting in the way of the 3D CGI art I'm working on.

So how do I stop the notifications from that one calendar (other than unsubscribing from it)?

TB 158.0.1, but this has been going on for a long time and a lot of TB versions. Windows 11 Home 26H2

I cannot receive mail from my Outlook.com account in Thunderbird. This does not appear to be a Thunderbird configuration problem.

Thunderbird 159.0 on Windows. IMAP: outlook.office365.com, port 993, SSL/TLS, OAuth2, username = full address SMTP: smtp.office365.com, port 587, STARTTLS, OAuth2, username = full address

The Microsoft sign-in window completes successfully and an OAuth2 token is issued and stored. Using the same token: 1. SMTP AUTH XOAUTH2 succeeds: 235 2.7.0 Authentication successful 2. IMAP AUTHENTICATE XOAUTH2 fails: NO User is authenticated but not connected. 3. POP3 AUTH XOAUTH2 fails with an authentication/protocol error

I also reproduced the IMAP failure with a raw IMAP connection, outside Thunderbird. A brand-new Thunderbird profile still fails for this Outlook.com account; a Gmail account in the same profile works normally. Thunderbird is up to date.

Outlook on the web works. IMAP is enabled in Outlook.com settings (toggled off and back on). The same IMAP failure happens on two different networks.

I have already contacted official Outlook.com support. They said IMAP is outside their scope as long as Outlook.com works in the browser, and directed me to Feedback Hub.

Is there any Thunderbird-side workaround, or any known Outlook.com IMAP OAuth2 bind issue and recommended next step?

Hi,

For both servers imap.exmail.qq.com / imap.263.net, when I click on the email subject in the email list during downloading processes (many emails headers are being downloaded but email body downloading is not completed), the email is broken without any content (only header).

I go to the web email server and move the email to another folder and then move it back to inbox. Then I delete the same email in Thunderbird and donwload again the email again, it's completely downloaded with the email body.

I don't have any issue with eM client or Outlook for such issues. Any possible setting to solve this issue?

Thanks.

After years of mailing committee meeting notices, suddenly in the last 2 weeks they are being 'failed' because of being 'too many' recipients (only 20 btw) and am being told 'try later'?! Pierre

I cannot find an article that tells how to change to a new email ISP/Email provider while keeping all of my local folders. I would think that this would be a very common need as users relocate to different areas for new job or whatever. It's personal with me, I will not use Gmail, Yahoo, or AOL as my primary email.