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Ive been sending a weekly invite message from Thunderbird to same 40 recipients - no prob until today, when i got this message:

Sending of the message failed. The message was not sent due to exceeding the allowed number of recipients. The server responded: Policy-SC01 You’ve reached your sending limit. Don’t worry, you can send again soon..

I contacted Virgin support who shared my screen and played around with some of the Thunderbird settings. No solution so they said contact Thunderbird support, hence message. At time of this message i cannot even send to one recipient......would appreciate advice on here if possible.

Thunderbird suddenly stopped working properly today, 15 September 2026. Webmail for the same email account is working normally: I can both send and receive messages. However, Thunderbird is having problems with both incoming and outgoing mail. • Thunderbird connects to the IMAP server, sometimes very slowly, but then does not retrieve new messages. • Sending a message from Thunderbird fails because it cannot connect to the outgoing SMTP server. • Thunderbird's own update also fails. This has never happened to me before. • I have restarted Thunderbird and also restarted the Mac, but the problem remains. • I have not changed any Thunderbird account settings. The fact that webmail is working normally makes me wonder whether this is a Thunderbird problem rather than a problem with the email service. Has there been a known Thunderbird problem affecting connections to mail servers or the Thunderbird updater, and could these problems be related

I reported this to you by last Friday but I have received no response so far. After reporting to you, I tried all possible trouble tests and checks, then took following steps. 1 - I deleted my copy of Thunderbird from my PC 2 - I loaded a new copy of Thunderbird - all went well 3 - But situation remains, the program opens, reacts very slowly to commands but I can not get into any functions. Thunderbird does not show any emails, nor can I read older emails stored on my computer 4 - I ask you kindly for speedy help, my email function is fully down. Yours - Jarl Jaatinen - Finland

In the last month or 2, when I delete an email it does not show in the trash folder. I can wait from 5 minutes to even the next time I reboot my puter to finally see it it trash. Sometimes it sends it to the all mail or important folder instead of trash. And if I delete from there, it still takes tons of time to end up in the trash folder...if it even gets there. This seems to be getting worse by the day. I have clicked repair folder, no change, I have cleared Thunderbird's cache, no change. It's also now taking way too much time to load an email that contains a picture. This happens with at least 3 of these gmails. I'm at a loss here and extremely frustrated and about to change these gmails from imap to pop. win10 and TB is up to date. But it doesn't compact folders as much as it used to either. Any help appreciated

In checking my email, I clicked on one that was from "Progressive" which is a valid correspondent but upon opening, it was from United Airlines, which is also a valid correspondent for me. I closed out Thunderbird and reopened but this did not resolve the issue. Is anyone else experiencing this issue?

This problem has not been resolved but continues. Please tell me in plain English what I can do to correct it, other than to abandon Thunderbird.

Using Mac Airbook iOS 15.6.1 Sequoia

This past Saturday (21st) I noticed it was taking longer to get emails from Spectrum. I had to click the Get Messages button several times and eventually the box to put in my password would pop up. After putting it in the emails would finally show up. This continued into Sunday, but by late afternoon I was getting no emails from Spectrum. I tried sending a test email from Thunderbird and got the following error message:

An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: impout007.msg.chrl.nc.charter.net cmsmtp [my IP address] blocked. Please see https://www.spectrum.net/support/internet/understanding-email-error-codes for more information. AUP#Out-1120.

I went to the Spectrum website to look up the error message and found this:

The IP address you’re trying to connect from has an issue with the Domain Name System (DNS). Spectrum requires a full circle DNS for emails to be allowed through. Verify the IP you’re connecting from, and check the IP address to ensure a reverse DNS entry exists for the IP.

At that point I called Spectrum tech support, spent about 2 hours talking to 3 different people, but I got no solution. I was able to verify my IP address is not blocked. I was basically told everything is fine on their end, so I should contact Thunderbird. All of my emails are still on the Spectrum website. I can send and receive on that site. No changes have been made to account settings or my password. I’ve tried to find an answer using Google and Youtube, but nothing so far. I did look on the Thunderbird forum, found a post from someone who was also having trouble with their emails and Spectrum this weekend. I’ve downloaded the latest version of Thunderbird, 153.1. One of the tech people suggested I use the Repair tool in Thunderbird on one of my folders. I wish I hadn’t. I used it on the Inbox folder and all of my emails disappeared in Thunderbird. They’re still on Spectrum’s site. If anyone has an idea for a solution I’d appreciate it.

As I was about to post this I opened Thunderbird and about half of the emails from my In Box have reappeared.

all emails that I send have no text appears, but 1 attachment shows. Click on the attachment and the text appears. I wanted the text showed in the email not attachment.

I was actively using Thunderbird in 2024-2025. Then I moved to Outlook. I had difficulty to move emails from Thunderbird to Outlook, so 2024-2025 emails remained in Thunderbird only. Last month my company did not extend Kylos domain subscription therefore Kylos will delete my emails from server soon. I'm afraid I will loose 2024-2025 emails then. Could you please advise / explain the solution not to loose my emails in Thunderbird. Server configuration IMAP. Emails moved from inbox and outbox to local folders, but for IMAP it may not be solution.

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

Thunderbird ver 115.18.0, on a Win7 machine, upgrading not an option

When opening Thunderbird I get a sign-in message, inserting my email address and clicking the next button I get the google error message.

When I try to start Thunderbird on my Windows 11 laptop it does not start properly It is haging ond after a whike i get a message that thunderbird does not respond ("svarar inte" in swedish). Sometimes if I try to reinstall Thunderbird it starts up, But today nothing happens.

After latest update Thunderbird cant send or receive emails. My settings are correct mail.charter.net port 993 outgoing mail.charter.net port 587.

Tells me I have a server error and is constantly asking for my password. HELP!!! I have been with Thunderbird since the beginning and have sent money to the cause, and now I need your help.

Thanks, Pam

Additional details:

• Operating system: Windows (please specify your Windows version if known)
• The issue started on August 25, 2026.
• Thunderbird becomes unresponsive shortly after startup.
• A “System Integration” prompt appears before Thunderbird becomes unresponsive.
• I cannot click any buttons once Thunderbird becomes unresponsive.
• I tested both available profiles (“default” and “default-esr”) using the Profile Manager, but the same issue occurred with both profiles.
• I also started Thunderbird in Troubleshoot Mode with all add-ons disabled, but the issue still occurred.
• I can force-close Thunderbird through Windows when it becomes unresponsive.
• I have not deleted or modified any Thunderbird profile files because I want to avoid losing existing email data.
• The profile containing my email data appears to be “default-esr”.

I would appreciate any guidance on how to identify the cause of this issue and restore Thunderbird without losing my existing emails.