OP:
As you posted in the beginning, you said your ISP (Burlington Telecom?) is going to discontinue email at the end of the year.
Well, ok.
Have they posted anything about what will happen to EXISTING email accounts?
Are they "handing over" the email system to another provider (such as Yahoo)...
or...
Have they said that it's all just going to "disappear", and that customers are on their own to handle it...?
I believe that Comcast discontined their own email servers a year or two back, BUT...
... they "transferred everything" over to the Yahoo email system.
I think ATT did that as well, some years ago.
Hmmm...
Did a little searching, and there's a pdf from Burlington on how to transfer emails to iCloud:
Also covers moving to Gmail (I wouldn't go there), Outlook (I wouldn't go there either), etc.