Could you please provide links to the following:

1. The email provider's website
2. The announcement you refer to in your first clue
3. The Spectrum website the support people refer to

Not sure I can help but if possible, any or all of those items might help me help you.

Thanks :)

Looks like `mobile.charter.net` is the outgoing (SMTP) mail server Spectrum want most customers to use.

https://www.spectrum.net/support/internet/changes-accessing-your-spectrum-email

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

How many `Outgoing Server (SMTP)` entries do you have?

What is your `Outgoing Server (SMTP)` set to for the charter / spectrum account?

1) The email provider is Spectrum: https://www.spectrum.net 2) Announcement of email changes: https://www.spectrum.net/support/internet/changes-accessing-your-spectrum-email 3) There are two differing ways to use email. With Thunderbird, the app downloads incoming emails from a Spectrum server, and uploads outgoing emails to a Spectrum server. What the Spectrum customer service staff is biased towards is the other way, which is to log into the Spectrum website using a web browser (in my case, Safari) and read and send emails without downloading.

Thank you for your time and attention.

There have been many posts about spectrum and charter. No one can give any real help, however, unless you share the settings you are using, in detail. Then it will be possible that suggestions will surface to assist you. Thank you.

Here is a screenshot of the outgoing settings. I hope that is what was requested?

Then we have this sort of Spectrum user issue as well. https://support.mozilla.org/en-US/questions/1437231

Earlier today PD posted a link to the Spectrum server settings on the spectrum web site. Those say clearly that Charter.net email addresses need to use mobile.charter.net as the server name. Do you see that there might be an issue with your choice of server? It also says that SSL should be used, yet your setting is for no connection security when it should be SSL/TLS

Then there is the initial issue you stated you had several charter addresses, so you need an equal number of charter outgoing servers configured. One for each email address (I would suggest named for make picking the right one easy) and then the correct one set in the identity part of the incoming account settings (the first pane above server settings). Note the sign in details for the SMTP server need to match the email address being sent from. You can not send emails from Billy@charter using the outgoing server credentials for Wally@charter.

There are nine email addresses that I access at Spectrum via Thunderbird (five of them very inactive because they were my deceased parents' accounts). I have adjusted all of them to mobil.charter.net Resultant error message when sending: "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mobil.charter.net failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again."

Then, I changed the security setting to SSL/TLS, and got the same error message. "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mobil.charter.net failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again."

There are nine email addresses that I access at Spectrum via Thunderbird (five of them very inactive because they were my deceased parents' accounts). I have adjusted all of them to mobil.charter.net Resultant error message when sending: "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mobil.charter.net failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again."

Could you please post another screenshot showing these changes?

If that's a bit awkward, could you please confirm the letter e is present between the words "mobil" and the first dot character? It's possible this is just a typo. Many Americans seem to pronounce the word mobile without using the last syllable correctly. It's possibly easier to remember the correct spelling by pronouncing it properly: "mo" as is, short for moustache, then "bile" as in the yellow/green fluid produced by the liver that most people spew out on to the innernetwebs :)

1) The email provider is Spectrum: https://www.spectrum.net 2) Announcement of email changes: https://www.spectrum.net/support/internet/changes-accessing-your-spectrum-email 3) There are two differing ways to use email. With Thunderbird, the app downloads incoming emails from a Spectrum server, and uploads outgoing emails to a Spectrum server. What the Spectrum customer service staff is biased towards is the other way, which is to log into the Spectrum website using a web browser (in my case, Safari) and read and send emails without downloading. Thank you for your time and attention.

Regarding the two means of accessing email, I believe you are referencing the two most common ways to access email, those being:

1. Via a website, "webmail", as popularized (for better and worse) by Gmail (although not the only way to access Gmail) 2. Via a dedicated email application

I agree that support staff could be inclined towards a webmail bias for the simple reason that this gives them one single point of reference to walk people through. This is unfortunate but also very understandable. However ...

The way that people access email is distinctly different from how it is managed.

Whether an email provider presents a webmail interface for customers, allows them to access email from a dedicated email app, or both, is generally irrelevant to how the mail is managed.

In short, the interface (webmail or app) is separate from the server.

Spectrum have documentation that details their server settings. These settings would not be published unless they were allowing people to access the mail server via a dedicated email app. So, the way you want to access your Spectrum mail on their server, via a mail app like Thunderbird, is fully supported by Spectrum. They might not promote it or support it well, but it's a legit use of their service, so you're all good.

The issues you are experiencing most likely boil down to tweaking some setting within Thunderbird. If possible, whilst I am completely empathetic that this experience is aggravating and Spectrum would ideally be much more helpful by walking you through Thunderbird set up for accessing their services, I reckon you can try to take a few deep, slower breaths and breathe a bit more easily because the problem will be sorted out soon :)

Be sure also to include the full email address in the SMTP settings, included the @ and domain name.