Tools|Options|Security|Passwords→Saved Passwords

Right-click or double click to edit a password. Note that you will need to change it in two places, one for incoming and one for outgoing.

But you need to go to your email provider and change it there too.

I have this problem too, I am running Thunderbird 49.0 and I cannot find any reference in any menus or tools for a password modification I do not want to take the offered option of deleting the account and then re-installing it as new because that would delete all of my saved email. There MUST be some way of editing the password which I was forced to change by MICROSOFT. When I try to get T'Bird to give me an option to input a new password I get this response :- Sending of password for user kevin2___@yahoo.com did not succeed. Mail server pop.mail.yahoo.com responded: and then nothing. Note that Microsoft simply insisted on a change to my Yahoo password because it was a reclamation email address and this error seems to lie ONLY with Thunderbird

if there is a password change Thunderbird does not use the word PASSWORD to flag it. How do I do this ?

Who told you to delete the account?

What is wrong with the directions I gave previously?

I was advised by Mozilla help to delete and reset the account. I have tried at least 6 times to change the password in the saved passwords list and have restarted Thunderbird 6 times and restarted the machine 3 times but it still cannot download messages. Have confirmed that the new password is correct and have also checked the SMTP and Pop server addresses. All looks good but still no email receipts

Could it be an error within my Thunderbird 49 ?