Verify your credentials using webmail.

Thanks for the comment...what do you mean "Web Mail"  ?? Thanks

Webmail means to access your email account with a web browser.

I can log into my email using my web browser with no poblem. However, when I use the same info in Thunderbird mail it says incorrect user name or password. I can't continue past that point until I resolve this.

Thanks..again...I will wait for your reply.

Are you still trying to set-up the account, or has the account already been set-up, and you get the error when trying to retrieve mail?

I get invalid username or password when I need to use for the first time on setup. No I'm only at the very beginning because it will not let me go any further. Thanks.

Did you enter your user ID in the correct format? Some mail servers expect the entire email address as user ID, others only accept the part before the @ sign.

When I check in via webmail I only use the first part before the @. I have tried it both ways on Thunderbird...neither on works. This is usually very simple I just don't understand why it doesn't work. Please try to help!

When trying to set-up the account, how do you do it?

Do you run the new account wizard?

https://support.mozilla.org/en-US/kb/automatic-account-configuration

Yes...use the wizard.. and click want to use existing email account

want to use existing email account

I don't understand that. Please follow the instructions in the article.

Thanks for all the help. I never really figured out what was wrong. I must have changed emails over 100 times and no problems. However, not on this one. So what I did is open a new email account at yahoo and BINGO...it worked the first time.

Thanks for all the help!!!!!

Yahoo (at least old accounts) have a setting on the web page to allow POP access. I wonder if that was your issue.