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Aloha. I'm helping a friend with setting up a new Windows 11 PC, and cannot get Thunderbird to connect to Spectrum's servers. I spent an hour on the phone with Spectrum support and they just gave up and said it must be an issue with Thunderbird. Here are the details:

- Brand new Dell 24 All-in-One EC24250 - Windows 11 25H2 plus all additional fixes. - All Dell drivers updated. - Thunderbird V155.0 64-bit

If I click on 'Get Messages' after a while I get: "Connection to server mail.twc.com timed out". I've gone into the config editor and changed mailnews.tcptimeout from 100 to 500 and still get the error.

In the Account Settings | Server Settings | Test server connection I get: An error occurred connecting to mail.twc.com:993.

I've tried this with both setting up a brand new account in Thunderbird, and also via copying the 'Thunderbird' folder from %appdata%\roaming from her old machine.

Email configuration (from Spectrum).

IMAP Settings Server name: mail.twc.com Port: 993 user name: abcd@hawaii.rr.com Connection Security: SSL/TLS Authentication method: Normal password

SMTP settings Server Name: mail.twc.com Port 587 Connection Security: STARTTLS Authentication method: Normal password

Can anyone help me troubleshoot this scenario?

Mahalo, Harry Z

This afternoon, without any warning, all my mail in every folder could not be displayed. This is the second time this has happened in the last month and a half. I have two mail accounts - one that goes through Yahoo and the other Gmail. No mail is displayed in either account.

When I run Thunderbird in troubleshooting mode, the mail does display. I then disabled the few addons that I use but that didn't make any difference. When not in troubleshooting mode, no mail is displayed.

Of course, there's "troubleshooting information" but that's way too technical for me to get anything out of it.

I've been a Thunderbird user for over 20 years and I would like to keep using it but this performance is discouraging.

What do I need to do to get past this issue? I'm assuming I'll be able to read an email response by using troubleshooting mode.

Thanks.

After swapping to The Bat some years ago I decided to come back to Thunderbird again. So I installed Thunderbird 155.0.1 (64-bit) on my Windows 11 PC, and gradually re-created and connected the the accounts I had on the back. I also installed the ImportExportTools NG addon, then exported my emails from The Bat to Thunderbird. So far so good. However for some reason I created an account twice. There are both for the same GMX account, but one is POP and the other is iMAP. This mistake probably happened after a long session of setting things up and I just forgot about the first account.

I looked through the Thunderbird help and the answer most given was to the Thunderbird menu, select Account Settings, swap to the account you want to delete, and then press the large red DELETE BUTTON on the top level of its settings (next to the DEFAULT button). I've tried this and it doesn't work. There's no confirmation dialog (which is what I was expecting) and if I close and reboot Thunderbird the account is still there.

How can this be fixed?

When I open Thunderbird it is sending my emails directly to the deleted folder. I have tried all-sorts and cannot find an answer. I transferred Thunderbird to my new PC and all was working okay for a few weeks then all of a sudden there were emails missing from my inboxes and I found them in the deleted folder. I am 76 years old and need an easy step by step solution please ..... John

I have settings from Greenby to set up server connections for a new account. They are validated by thunderbird but, after, entering my greenby password, generates the error, below, which greenby claims is a thunderbird problem.

"Component returned failure code: 0x804b000a (NS_ERROR_MALFORMED_URI) [nsIIOService.newURI] Show less

Component returned failure code: 0x804b000a (NS_ERROR_MALFORMED_URI) [nsIIOService.newURI]"

Now my greenby password works on their systems

Now I'm very new to Thunderbird so not familiar with the commands

Any one any ideas ?

My desktop Firefox (version 155.0.1) has recently became unable to consistently access the Web site at this Web site this Web site. Chrome successfully accesses the site 100% of the time. Firefox's connection failures are intermittent, unpredictable, and usually go away on their own after varying time intervals (sometimes can't connect for up to 24 hours). I see status messages saying Firefox is trying to connect to the site, but it eventually gives up and times out.

I cleared the Firefox cache, but that had no effect. I don't recall making any significant changes to the Firefox settings lately. Any suggestions on what to look at/try would be greatly appreciated.

(Yes, I know the site doesn't use https: Its protocol is outside my control).

In TB 155.01 when I click on Delete the email leaves my Inbox but does not display in the Deleted folder. If I look at Properties in the Deleted folder it shows the correct number of messages in there but the messages themselves do not show in the right hand window. Thus there is no way of seeing what the messages are, just the total quantity in the folder.

I have many years and email accounts on my old WIN10 workstation running all POP installations.

I have a new workstation with WIN11. Is it possible to install TB on my new workstation with my accounts installed as IMAP and keep the same folder configuration? I have many email folders and filters setup on the old workstation installation.

I would appreciate any installation recommendations. I've been using TB for years and would like to keep as much of the current configuration as possible.

Hello fellow Thunderbirds,

I have been using Thunderbird for years and had thousands of emails in quite a few folders, with a shit-tonne of filters etc. My emails were running pretty well. I only use two addresses, but the folders help manage everything.

I just got a new computer last week. Prior to switching over to the new computer I read through the 'Export your Thunderbird Profile' help page, and the 'Move Thunderbird data to a new computer' pages. I've tried to follow all the info there (with a glitch, explained below).

I am using a Windows system and have gone from Win10 to Win11.

I have the following data:

• Mozilla Maintenance Service (in Program Files (x86) ).
• Mozilla Thunderbird (in Program Files (x86) )
• Thunderbird (In Users/Username/AppData/Local/Thunderbird) (Contains 'profile' and 'updates'

I tried to swap the above data into the same spots on the new computer, but alas, it's not working. I *may*, however, have fucked it up myself...

So... When I got the new computer, I immediately downloaded Firefox, but, alas, I entered my email's details before closing it down. It did download a few off the server, but only a day's worth (before I realised I screwed up).

As soon as I realised I'd mucked up, I uninstalled Thunderbird and deleted the files on the new computer (you know how when you download it doesn't always remove all the stuff, so I tried to do this).

I reinstalled Thunderbird, but closed it prior to loading the email addresses on (as instructed). I then transferred all the above data into the corresponding file areas on the new computer. However, everytime I try to run the program it just goes to the standard open screen (with the popup that prompts you to enter your email addresses and details into it - see image, below, in case I'm not explaining it right).

Anyway, I'd appreciate any help you might be able to give me as I'm desperate to get my emails running again and have access to all the saved emails which were in my system. Kindly. Larysa.

I can't see bookmarks on the RH menu but only on the LH when I click 'manage bookmarks. How do I move the bookmark folders so that they appear on the RH. This happened at the last software update.

Recently I posted about this problem here: https://support.mozilla.org/en-US/questions/1580858 In sum, I was having problems both in downloading messages from the Spectrum server and also with sending messages. I've attached screenshots of the error messages.

Matt and David kindly posted some helpful responses. The problem then seemed to spontaneously solve itself and I breathed a sigh of relief. Then a few days later it re-appeared.

This time it's not quite as bad in that I'll get the error messages but then usually a few minutes later I can download the messages or send an email. But it's still a real problem.

I called Spectrum again and this time the rep was adamant that if I can still use the Spectrum webmail feature (and I can), then it's not a Spectrum issue.

Last time Matt asked about my antivirus. I use Windows Defender (and occasionally do a manual scan with Malwarebytes free version), so if I understood him right, I should be OK as far as antivirus interference.

Matt also suggested I set TB so that I download messages at startup and every 15 minutes. I was set to every 10 minutes so I changed it to 15.

Matt said for me to check the Activity Manager. I've attached a screenshot of what that showed a few minutes ago. But I should note that this was after an error message displayed but my email downloaded anyway.

Finally, Matt said I should check the Error Console (Control + Shift +J). I've attached a screenshot of that. He also said I should use the trash can to clear it, so I did. He then said to press Shift + F5 to attempt to get my messages. But on my laptop, F5 just dims the display so no dice on that. But I have a second laptop and F5 is "neutral" on that one so I tried it there. I didn't get any new error message.

However, one of the screwy things is that sometimes I get all my messages as normal, but only after the "Can't connect to the server" message displays. And that's what happened with my second laptop above.

I hope I've provided better info. this time. And I hope you gents can help me with this mess.

Thanks,

Andrew

There is seriously something wrong with the way Firefox operates. There is nothing wrong with the following site so why am I seeing this message?

Be careful. Something doesn’t look right.

Firefox spotted a potentially serious security issue with news.sky.com. Someone pretending to be the site could try to steal things like credit card info, passwords, or emails.

news.sky.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site. Advanced What makes the site look dangerous?

The site is set up to allow only secure connections, but there’s a problem with the site’s certificate. It’s possible that a bad actor is trying to impersonate the site. Sites use certificates issued by a certificate authority to prove they’re really who they say they are. Firefox doesn’t trust this site because its certificate isn’t valid for news.sky.com. The certificate is only valid for: . What can you do about it?

news.sky.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site.

How do I make firefox my default browser when using search bar on task bar for windows 11. Although all my settings have the default browser as firefox microsoft, edge is what comes up when I use the taskbar search window.

I have Thunderbird 153.2.0esr which runs 2 Email filter (on Inbox and on Outbox)

These filters worked for years.

Suddenly, about at the end of July 2026, the stopped working.

I suspect that one of the latest release of Thunderbird make them stop working.

Is it possible? Any suggest?

Also the filter log registry is empty.

I’m trying to find the backend email address configured for a website’s contact form using Inspect Element/Developer Tools. I’ve checked the page source and searched through the available HTML, but I’m unable to locate the email address or identify where the form submissions are being sent.

Could someone please guide me on where I should look or which files/settings I should check to find the form’s destination email?

Hi everyone,

I'm facing an issue with website screen responsiveness in Mozilla Firefox. A site that is supposed to be fully responsive and mobile-friendly displays properly on my 24" desktop monitor (photos, alignment, and overall design look fine). However, when opening the exact same URL in Firefox on a 13" laptop screen or a mobile device, the visual design breaks—layouts overlap and images get distorted.

Has anyone encountered this issue in Firefox with certain display scales or viewport media queries? Is there a known fix or setting in Firefox (or layout tweak) to resolve this layout breakdown on smaller screens? Any advice or troubleshooting steps would be greatly appreciated!

I read that "Once a message is marked as junk, it will disappear from the main inbox view and be relocated to the specified junk folder." However, that does not happen. Once I mark a message as spam, it just has a red mark next to it and I have to go to Tools and have it "delete mail marked as spam from folder".

Hi, I have a problem with hundreds of Casino type emails filling up my spam folder so I asked AI for help. AI suggested I change my mail handeling from Standard to Strict. Ever since then it will not stay on Standard, it keeps reverting to Strict every time I try to revert it back, therefore all my wanted emails go straight to Spam. I need to check through heaps of Casino emails and take out my wanted emails which is so annoying!! How can I change it back so as it stays changed? I will not ask AI for help ever again, it was working fine until I changed it. Ugh.

I am not sure how to find out what version Thunderbird is, how do I find out please. It should be up to date as I have everything set on automatic up date.

I use an HP Laptop, windows 11.

Hello

I use Thunderbird (153.2 0esr) on a win 11 PC.

I have some POP email accounts with btinternet which work.

I want to change. them to IMAP accounts using the same email addresses.

Before I do this I have several minor problems within Thunderbird, which I would like to sort out before copying the Thunderbird files as a backup.

Rather than list them all, it's possible that fixing the first may solve others.

When I open Thunderbird I see this message... see FIRSTCalendar if it hasn't been inserted into the text

I have never (knowingly) used BT's calendar. Clicking cancel removes the report and does not stop any of the BT mail accounts working.

I tried using the username and password of the default account but password of the default account without success. At a later stage this appears...

See SECONDcontacts if not inserted here

The address displayed is one that I have deleted from my BT Email account.

It is no longer shown as one of my BT accounts in the email management page in MYBT or in Thunderbird

Again, clicking Cancel does not stop my BT email accounts working.

Any suggestions how to fix this, would be welcome.

Cheers

Dave