This likely isn't Thunderbird; it's more likely your email provider. Some email providers, such as Gmail and AOL (and others, I'm sure) require a different password than the one used for web access, which means your phone may be working, but not your PC. If you share your email provider, someone here may have a suggestion.

My internet provider is Rogers.com in Canada

Thunderbird asks for credentials only if the email host denies the credentials already available to Thunderbird. This is sometimes caused when email hosts change their login procedure. If you have a specific issue, please post more information.