Have you tried without the assistance of your antivirus program? They tend to block port 25 and can make a complete hash of actually sending encrypted mail with they self signed certificates.

Thanks for the idea. This machine currently has no anti-virus, windows or otherwise, no anti-malware, no firewall turned on, rather running wild right now trying to get this working. Remember, I have five email accounts in T-bird and only the one account isn't working. Furthermore it was fully functional until 8/22/2024.

Port 25 is verified usable by testing with one of the other accounts.

Frustrating as it may be, antivirus is not the answer.

Thanks.

then I suggest logging the actual connection. See https://wiki.mozilla.org/MailNews:Logging In a nut shell use the Config Editor to set the preference mailnews.smtp.loglevel, string, to All Open the error console (ctrl+Shikf+J) Clear it using the Trash can icon on it's toolbar Try your send Check the error console.

Note Right click allows you to copy everything to the clipboard and paste into a message here or into notepad to make a log file.

Done, and done. Here is the result. Should I share this with the tech support for the domain email host or shall we work it first?

window.controllers/Controllers is deprecated. Do not use it for UA detection. 2 blank

mailnews.smtp: Command failed: 554 us2.outbound.mailhostbox.com ESMTP not accepting connections; currentAction=_actionGreeting SmtpClient.sys.mjs:602:19

mailnews.send: Sending failed; An error occurred while sending mail: Outgoing server (SMTP) error. The server responded: us2.outbound.mailhostbox.com ESMTP not accepting connections., exitCode=2153066732, originalMsgURI= MessageSend.sys.mjs:319:32

sizeToContent() is deprecated and will be removed in the future. commonDialog.js:132:10

This page is in Quirks Mode. Page layout may be impacted. For Standards Mode use “”. SmtpClient.sys.mjs

I decided to check info: https://support.mailhostbox.com/email-administrators-guide-error-codes/

554-mx1.mailhostbox.com ESMTP not accepting connections OR 554-us2.mx1.mailhostbox.com ESMTP not accepting connections OR 554-in.mx1.mailhostbox.com ESMTP not accepting connections When sending an email to a recipient within our mail hosting servers, sender may receive a bounce back stating ESMTP not accepting connections. The error indicates senders IP address is suspected of sending spam and is blacklisted.

Check to see if the sending/your IP address has been blacklisted. It's possible the mailhostbox server has spam filters and your IP address has been flagged up so you are being blocked by mailhostbox themselves.

It's entirely possible that your tech could send but you cannot because you are not using same IP. I'm surprised the Tech did not think of that option nor seemed to be aware of their own information.

Info says: To resolve this issue, please perform the steps below: 1. Check sender’s IP address, if it is blacklisted in any RBL (Realtime Black List): http://mxtoolbox.com/blacklists.aspx. Ask sender to submit an IP removal request to RBLs. 2. Check IP reputation on mail filters by contacting CSI and get the IP delisted by visiting the following URL: https://csi.cloudmark.com/en/reset/ by providing the sender’s IP address.

There is also spamhaus: https://check.spamhaus.org/

mxtoolbox says; Checking drachenfelspress.com which resolves to against 9 known blacklists... Listed 0 times with 0 timeouts

Spamhaus says no issues for www.drachenfelspress.com and no issues for my IP which is dynamic anyway but right now it is no issue and I cannot send.

I have contacted CSI even though pointers would indicate that is not the issue.

Received this:

Cloudmark Sender Intelligence and why your email may have been blocked: FAQ. Warning: The submitted IP (65.111.41.146) appears to be dynamic

The DNS pointer record for this IP (dyn-65-111-41-146.midcentury.com.) appears to be dynamic. Cloudmark will not remediate dynamic IP addresses.

So... no joy yet.

What I am seeing is your provider is refusing to accept sending mail because their spam filtering says you send spam. I suggest you seriously need to have a discussion with them.

My guess is they are applying transmission/relay SMTP standards to email submission. It appear to be a new cottage industry in providers who expect everyone to be using web mail. But this is only my interpretation of the information supplied here in the last day or so.

Thanks Matt but they say no.

Drachenfels Press domain has an extremely low smtp volume because it is used almost exclusively to handle communications between editors and authors.

Further, they say, if that were the case they wold have the same problem in the cloned account when they troubleshoot; which they point out works even with several different setting sets.

I thought Toad-Hall was on to something there. Alas.

re : dynamic IP

Are you using a VPN ?

I've come across people who get blocked by server because they use VPN and server thinks the sender maybe hacking your account or a spammer etc.

Please switch off the VPN. REstart Thunderbird Test a send.

Good info for the next guy, but...

No VPN.

The point is - it is their server blocking you and their own help mentions the exact failure message which you see. That error is coming from the server not Thunderbird.

The error message is implying their server thinks you are a spammer and it has something to do with your IP. Hence why their tech could not replicate.

You mention a dynamic IP address. It was a possibility it might be due to the use of VPN - I discovered Norton had auto enabled one on my computer. Caused no end of headache until I found what Norton had done.

Please set up to use a static IP, so server recognises it is you.

What Anti-Virus do you use ? Is that Anti-Virus scanning out going mail ? I've come across people who discovered their Anti-Virus was appending stuff to their emails and it was that 'this email has been scanned by...bumph added by the AV which was causing their emails to get labelled as spam. Please check - stop any AV etc from scanning outgoing mail.

No antivirus on this desktop. No windows defender active. Firewalls turned off. No VPN, no Nortons, no Avast, not Email scanning. NADA.

I agree the issue is on their end. The problem is every time I email them they start at square one... and send the same BS suggestions.

Received this: Cloudmark Sender Intelligence and why your email may have been blocked: FAQ. Warning: The submitted IP (65.111.41.146) appears to be dynamic The DNS pointer record for this IP (dyn-65-111-41-146.midcentury.com.) appears to be dynamic. Cloudmark will not remediate dynamic IP addresses. So... no joy yet.

Previously you mentioned "mailhostbox.com " But that IP belongs to "midcentury.com"

Is your website hosted by midcentury.com ?

Who provides your internet? What is your connection with midcentury.com?

I still think this is due to the IP address - have you tried using a static IP ?

while I do not purchase a static IP address MidCentury Communications (indeed most fiber connections) may as well be static. The only time you get a new IP is when there is a system issue or if you put in a trouble ticket, which I have done, and did again today. By noonish I should have a new IP functional AND he time to try it. Very busy morning this AM.

MidCentury Comminications is my ISP The Domain is registered through Active-Domain < have worked with these guys for decades. They do not host. Mail host for this domain (active-domain's default) is Mailhostbox.com Website is hosted at companycasuals.com

Going to bang my head if this all comes down to needing a new IP socket.

Banging my head.

After a long conversation with my ISP we swapped IP numbers a half dozen times in a half hour or so and poof. Everything works again.

Banging my head.

Good to hear it's all working again. I thought it was definitly to do with the IP address.