

Using OAuth2 for "secure authentication" will popup a window for your password using your systems default browser. You can do that by replacing with as the username in Tools -> Account Settings -> Server Settings. If you're using the same Gmail POP account with multiple email clients you need to enable recent mode in order to let each email client access all of the messages in that account.

You can create a new account by pressing the Add Mail Account button in Tools -> Account Settings -> Account Actions. To add an account in Thunderbird you need to have a Gmail webmail account, create either a POP or IMAP account in Thunderbird and then enable it in Gmail settings using a browser. Gmail provides free webmail accounts and POP, IMAP and SMTP servers.

This article was written for Thunderbird but also applies to Mozilla Suite / SeaMonkey (though some menu sequences may differ).
