I followed a previous post about changing the Server settings from NormalPassword to Oauth2. This value is not available.

OAuth2 authentication is only available for IMAP accounts (and SMTP). It isn't available for POP. Presumably your account is POP.

Under Server Settings, authentication methods available are Normal Password, encrypted Password, Kerberos, and NTLM.

Use 'Normal Password'.

If this still doesn't work please post your Troubleshooting Information. At the top right of the Thunderbird window, click the menu button , then select Help > Troubleshooting Information. Press the "Copy text to clipboard button" and paste the information into your reply.

I nitice your reply to a previous questioner, so I'm sending my troubleshooting info because my password always seems to be wrong on this new lapgtop.

 Application Basics

   Name: Thunderbird
   Version: 17.0.8
   User Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20130801144703
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Crash Reports: about:crashes
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (imap) imap.gmail.com:993, SSL, passwordCleartext
     OUTGOING: smtp.gmail.com:465, SSL, passwordCleartext, true

   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

 Extensions

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     browser.cache.disk.smart_size_cached_value: 358400
     extensions.lastAppVersion: 17.0.8
     font.name.monospace.el: Consolas
     font.name.monospace.tr: Consolas
     font.name.monospace.x-baltic: Consolas
     font.name.monospace.x-central-euro: Consolas
     font.name.monospace.x-cyrillic: Consolas
     font.name.monospace.x-unicode: Consolas
     font.name.monospace.x-western: Consolas
     font.name.sans-serif.el: Calibri
     font.name.sans-serif.tr: Calibri
     font.name.sans-serif.x-baltic: Calibri
     font.name.sans-serif.x-central-euro: Calibri
     font.name.sans-serif.x-cyrillic: Calibri
     font.name.sans-serif.x-unicode: Calibri
     font.name.sans-serif.x-western: Calibri
     font.name.serif.el: Cambria
     font.name.serif.tr: Cambria
     font.name.serif.x-baltic: Cambria
     font.name.serif.x-central-euro: Cambria
     font.name.serif.x-cyrillic: Cambria
     font.name.serif.x-unicode: Cambria
     font.name.serif.x-western: Cambria
     font.size.fixed.el: 14
     font.size.fixed.tr: 14
     font.size.fixed.x-baltic: 14
     font.size.fixed.x-central-euro: 14
     font.size.fixed.x-cyrillic: 14
     font.size.fixed.x-unicode: 14
     font.size.fixed.x-western: 14
     font.size.variable.el: 17
     font.size.variable.tr: 17
     font.size.variable.x-baltic: 17
     font.size.variable.x-central-euro: 17
     font.size.variable.x-cyrillic: 17
     font.size.variable.x-unicode: 17
     font.size.variable.x-western: 17
     mail.openMessageBehavior.version: 1
     mail.winsearch.enable: true
     mail.winsearch.firstRunDone: true
     mail.winsearch.global_reindex_time: 1522941438
     mailnews.database.global.datastore.id: a93c6756-8f6e-4fbc-8ae7-3d76edfe9af
     network.cookie.prefsMigrated: true
     places.database.lastMaintenance: 1522936015
     places.history.expiration.transient_current_max_pages: 103793

 Graphics

   Adapter Description: Intel(R) HD Graphics
   Vendor ID: 8086
   Device ID: 5a84
   Adapter RAM: Unknown
   Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igd12umd64 igdumdim32 igd10iumd32 igd10iumd32 igd12umd32
   Driver Version: 22.20.16.4735
   Driver Date: 7-7-2017
   Direct2D Enabled: Blocked for your graphics driver version.
   DirectWrite Enabled: false (10.0.15063.0)
   ClearType Parameters: ClearType parameters not found
   WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics) -- OpenGL ES 2.0 (ANGLE 1.0.0.1242)
   GPU Accelerated Windows: 0/1

cryptogram,

please start a new topic for your problem. https://support.mozilla.org/questions/new