There has been some confusion on what passwords are used on a computer.
1) ISP is a local telephone company: centurylink
2) OS is XP
3) Email client latest Thunderbird
4) email has worked without fault for months
5) computer was off for a week and email was handled from a guest computer using the centurylink home page and email service, using what I'll identify PW1

On returning home Thunderbird was unable to communicate with the ISP for email. The failure message to connect to the ISP email gave me a chance to input a password (to the ISP). I put in PW1 and the email downloaded. However, I can not send a message and while a similar failure results (Login failed) the clicking on the button "enter new password" doesn't produce a field to send the "new password".

Checking Thunderbirds "options/security/password/savedpassword I find for centurylink PW2,not PW1. Could this be the problem, on trying to send email PW2 is being sent even though I had just a few minutes before set PW1 to receive email? How do I change the Thunderbird savedpassword?

Hum, typing it just occurs to me, erase the saved password in Thunderbird and the next attempt to send email will give me a chance to input PW1 and that will be saved for future use.... I'll post this anyway as this still seems strange, but that could be because two different people are working this problem, the user, and me. She may have changed to PW1 at the ISP when on the guest computer.. ??

Tx.
Jerry