This solved the problem for another person:

Access your mail through the webmail interface. In the webmail page, go to preferences > mail. Near the bottom of the page is a section for "Access from other mail clients". Check "enable POP access".

My wild guess is that Rogers made a change after they bought Shaw.

Does that fix the problem?

Thanks for your reply. That is how my configuration is set. Apparently Shaw/Rogers is having an internet issue and others clients are having problems. I was told to try again tomorrow.

I hope Shaw/Rogers gets their act together soon.

Despite more than two hours in a chat with Rogers/Shaw it still doesn't work. They of course blame Thunderbird. I can send email but not download new messages since two days ago. I made no changes to anything to cause this. I can log in to MyShaw and open and fully use Webmail so at least some passwords are correct. Extremely frustrating! I would dump Shaw/Rogers but I don't want to change the email ID I have used for years.