Did you mean windstream.net maybe? You've spent a good number of words describing how much time you've spent on this and yet nowhere have you said what error message are you getting, if any…

Yes I meant windstream.net. The error messages I get are: Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) timed out. Try again. or Login to server smtp.windstream.net with username xxxxxx failed. The login and password I am using works fine in the web browser.

OK. I'm seeing conflicting info about what the right settings are supposed to be. This would seem to be the official settings page, but the information provided there is incomplete at best:

https://www.windstream.com/support/my-account/email-101/what-server-settings-do-i-use-for-windstream-email

And there is this, which shows more complete info, but the server names there are different:

https://www.getmailbird.com/setup/access-windstreamhosting-com-via-imap-smtp

If you have a sheet showing what the right settings are supposed to be (not settings you've been told to use by phone), and post a screenshot of the outgoing (SMTP) server settings you're trying to use in Thunderbird, we may check whether they're correct and what it is that you could be missing.

Read the following article in the meantime to see possible causes of the problem:

https://support.mozilla.org/kb/cannot-send-messages

In particular, if you're using a VPN, disable it and see whether that makes the problem go away. If it does, check whether your VPN has an option called split tunneling which would allow you to let Thunderbird bypass the VPN.

I'm not using a VPN also not using windstreamhosting.com just windstream.com. I do not have a sheet showing correct settings unfortunately I tried changing smtp setting to smtp.windstream.netport, SSL, port 465 (as outlined in your first link) got this response: < Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) smtp.windstream.netport failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again.> Talking to their tech support they recommended smtp.windstream.net, SSL , 465 or port 587. Tried them all to no avail.

I said the information provided in the first page I linked was incomplete at best, but it's mangled:

Where it says: imap.windstream.netport: (SSL) 993 It should say: imap.windstream.net / port: (SSL) 993

Where it says: smtp.windstream.netport: (SSL) 465 It should say: smtp.windstream.net / port: (SSL) 465

So it seems the settings you should use for the outgoing server are the ones you say you're using:

smtp.windstream.net 465 SSL/TLS

If your OS is Windows, you may try starting in Safe Mode with Networking mode. You may have to connect your computer to the router with an Ethernet cable, WiFi is disabled in Safe Mode:

https://support.microsoft.com/help/12376/windows-10-start-your-pc-in-safe-mode

That would let you check whether there is an antivirus or some other software you have installed that's blocking the communication between Thunderbird and the SMTP server.

Well I finally got it to send. I don't know why it stopped in the first place. I have to use pop.dejazzd.com and smtp.dejazzd.com without SSL instead of pop.windstream.net and smtp.windstream.net even though Windstream told me I could use windstream.net with SSL.

Thanks for the feedback. I'll take note in case someone reports having the same problem with that particular email provider in the future.