What OS are you using? What version of Thunderbird are you using ? Are you talking about an imap or pop mail account? Do you mean you cannot download any emails? Is the problem just downloading mail OR do you also have a problem sending email?

Are you able to download when you start Thunderbird, but it fails to download subsequently? What error message are you getting when you click on 'Get Messages' ? Post an image of the error message OR tell us the exact error message word for word verbatim.

In Thunderbird

• Help > Troubleshooting Information
• Scroll down to 'Mail and News accounts' section
• Either copy all the data in that section and past it into this forum OR post an image showing data in the section.

Comcast uses Xfinity server.

• Logon to the comcast webmail account via a browser.
• Please confirm you can access the account - this proves the password is correct and you know it.
• Then use info at the following link and confirm you have enabled third party access.
• https://www.xfinity.com/support/articles/third-party-email-access

Confirm third party access checkbox has been selected. Whilst logged on to webmail account....confirm there are new emails which have not been downloaded to Thunderbird account.

Check to see if the download problem is because you are not actually receiving any emails on server. So whilst looking at webmail account... If you have reached your quota limit - used up amount of allowed stored space on server then server cannot accept any emails until you make some space. I ask this because Thunderbird will not be able to download if nothing is able to arrive on the server. You would need to delete a load of emails off the server to create some space. If you use a Pop account then you are ok as emails are stored on your computer, BUT if you use an Imap account in Thunderbird then it can only display whatever is on server - in which case - in Thunderbird, get copies of important old emails 'Copied' into a folder in 'Local Folders' account BEFORE you delete them off the server.

Report back on whether quota had reached max and no new mail on server.

When you get an email from the forum - do not use the 'Reply' option. You need to use the link in the email content - I think it's a blue text link that says something like 'this does not solve problem' and that will open a link to this question in the forum.

Thanks for responding.

Our computer is using Windows 11. Thunderbird version is 128.8.1esr. It is setup as POP mail account. What is happening is that when we bring up Thunderbird on the computer, it tries to connect to Comcast but says the password is invalid. It is not because it is the same password used to logon online. I can send emails, and whatever emails were downloaded via Thunderbird prior to our issue are still visible and available to read.

Here is the information from selecting the troubleshooting section in Thunderbird as you indictated:

Mail and News Accounts ID Incoming server Outgoing servers Name Connection security Authentication method Name Connection security Authentication method Default? account1 (pop3) mail.comcast.net:995 SSL/TLS Normal password smtp.comcast.net:465 SSL/TLS Normal password true account2 (none) Local Folders None Normal password account3 (pop3) mail.comcast.net:995 SSL/TLS Normal password smtp.comcast.net:465 SSL/TLS Normal password true

I don't know what the account2 is. I do know a while back I added my gmail address to Thunderbird but deleted it. The account 1 is most likely my email address and the account3 is most likely my wife's email address.

I connected to the website you provided and the third party access allowance is checked. I know my wife and I have a lot of emails either read or unread, but as you indicate, they should be on our computer (POP setup). New emails are being loaded to our inbox when we logon online to xfinity email.

For what it is worth, we are also having issues accessing comcast through our iphones. There we either get a message that "Your IP is on a blocklist" or a message "Server code ALERT, server message "Temporarily blacklisted IP Address - try again later".

I called Xfinity and they will not even begin to help. They indicate it is beyond their control.

Let me know if you need more information. Sam Orner

I've checked mine and my wife's email quota on Comcast. There are emails on Comcast's server for my wife from months back but her quota is 4% of 10g. My quota is 1% of 10g. mine is just since we've had the issue last weekend. Don't know why my wife's account has so many email, but has not reached the quota.

re: server settings Server name, port etc - All looks correct.

re : Info supplied: account2 (none) Local Folders None Normal password Your query: I don't know what the account2 is. Answer: It's the 'Local Folders' account which Thunderbird creates by default. It's an account where you can store emails eg: Imap users may need to get copies of important emails stored in a location that is independent of the server. Pop users may use if they created deferred accounts. Basically anyone can use it to store emails - archived emails - important emails - emails they want to keep but have got rid of the mail account.

re :I connected to the website you provided and the third party access allowance is checked.

Good because that proves the password is valid and allowing third party access is a requirement to allow Thunderbird access.

re : "Your IP is on a blocklist or a message "Server code ALERT, server message "Temporarily blacklisted IP Address - try again later"."

Please note the error message that you're seeing is an internal message from the provider (Comcast). Their own server spam filter has got your IP blacklisted which is odd because maybe they are your ISP or maybe a VPN is operating and has triggered a problem?

You can check the IP blacklisting using this link: https://check.spamhaus.org/

VPN IP issues are very common when the user is using a VPN and useris trying to get mail into an email client. Servers do not like VPN because they mask the users real computer IP address and use a one provided by the VPN. Servers do not expect anything other than the computers real IP address, so they think you might be a hacker and they auto block access to the account. In other words, your password is ok but server is blocking access.

You need to find out if you have deliberately or inadvertantly switched on/enabled a VPN (Virtual Private Network) on your computer. I did find this link that may help: https://support.microsoft.com/en-gb/windows/connect-to-a-vpn-in-windows-3d29aeb1-f497-f6b7-7633-115722c1009c#windowsversion=windows_11

Many Anti-Virus products now offer a VPN and in some cases I've come across, that VPN was auto enabled. eg: Norton365

If you have really checked your computer and there is no VPN then.... Please try to get a new IP number. Often this can be achieved by switching off computer and switching off your hub/router. Wait a short while maybe have a cup of coffee then restart the router and once it's up and running, start computer and then restart Thunderbird.

The issue has been resolved. The error on our phones directed us to a spamhaus.org website with an IP address. That website said one thing to do was to contact our ISP to have our IP address changed. I called my ISP, they reset the router IP address and all is working properly both with Thunderbird and with receiving email on our cell phones. As a side note I had Malwarebytes installed on my home computer and it established a VPN setup for me. The IP address was in Stockholm, Sweden! That IP address was the one that was being blocklisted on our phones and obviously causing the issue on our home computer. Thanks for your help.

Sam