Try with mobile.charter.net, 587, STARTTLS, normal password, email address.

Settings depend on the domain of your account:

https://www.spectrum.net/support/internet/email-settings/#/mobile-email-settings

Been there, done that multiple times. Just as a clarification, this is a PC install, not mobile. As a long shot, I want to try and delete/re-enter the smpt. password, but all the tutorials on-line seem to be out dated and the menu options don't match my version. I am running version 140.1.0esr

Settings/Privacy & Security, Saved Passwords, to remove and edit passwords.

The settings in the Spectrum link apply to mobile and desktop apps.

I was at that page a few times during one of my banging my head on the keyboard sessions. It does not have an entry for the smpt server. Should there be one? I may have deleted in already. I have tried so many different things, I don't remember what I have or haven't tried already. I probably have at least a full day of time fighting this over the last 7-10 days. The frustrating thing is that it was working fine, the suddenly it was not.

Dale

I think I got it. I have a decade old profile in Thunderbird that I used temporarily during a motherboard/ hard drive swap out. The accounts were outdated, so I set-up a new account. When it asked, I let it auto-configure the router settings just to see what it came up with. Those settings worked. I went back to my current profile and changed the settings to match, and they worked. there are two differences from what I had, 1) instead of smpt.charter.net, it was mobile.charter.net. 2) instead of the default port for SSL/TLS (465) it used 587. The question is why a working configuration suddenly break?

The fun of computers.

Thanks to the people that tried to help.

Dale