I'm assuming you use Windows OS unless you state otherwise. I'm also assuming you are using an up to date version of Thunderbird. I'm assuming you do not allow anyone else to use your computer OR if they do - they do not use your own User Account on computer. When you logon to computer it asks you for a password to access your computer User Account and see desktop. This means there is a level of protection for all documents etc in that User Account. No one else should have your personal User Account password, so they do not get any access to your desktop environment. When you run Thunderbird and want to access saved passwords, when you click on 'Saved Passwords' it should only display the username account data - not the actual passwords. But when you click on 'Show Passwords', it should ask for the Windows User Account password in order to display the passwords. This a another level of protection just in case someone is looking over your shoulder at this moment in time and you do not want them to see the actual passwords. So you can cancel if required. You also have the option to completely remove that Windows password request. You will need to enter the computer User Account password in order to access and disable it. This may be ok and suit you, if you are the only person using computer and no one else has your User Account password and you do not leave computer switched on and logged on to your User Account whilst you are not present. There is also an option to set up a 'Primary Password' which would operate instead of the Windows OS request for computer user account password. It does the same thing. The 'Primary Password' is not a mail account password, it's something you set up as a separate access level of security. This should be set up if others have access to your computer and access to your computer User Account password - unusual but possible. The Primary Password is asked when you start up Thunderbird as it will use password to access and download emails, but it is not a login to Thunderbird. It's usually asked once per session when you first start up Thunderbird or if you specifically want to see saved passwords. You do not have to enter it. Thunderbird will still proceed to download mail. Info on Primary Password: * https://support.mozilla.org/en-US/kb/protect-your-thunderbird-passwords-primary-password Please note: The Primary Password does not prevent access to Thunderbird, so you should still be able to see emails etc. If you are the only person using your computer then a Primary Password is not really necessary as it's only stopping you from seeing your own mail account passwords. But I would advise you ensure you have a computer User Account password as it offers protection to all your documents on your computer.