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.

(Everything wont fit injust one reply so here is part 1)

 Application Basics

   Name: Thunderbird
   Version: 45.8.0
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20170305125302
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

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

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

   account3:
     INCOMING: account3, , (imap) imap.googlemail.com:993, SSL, passwordCleartext
     OUTGOING: , smtp.googlemail.com:465, SSL, passwordCleartext, true

   account4:
     INCOMING: account4, , (imap) imap.googlemail.com:993, SSL, passwordCleartext
     OUTGOING: , smtp.googlemail.com:465, SSL, passwordCleartext, true

   account6:
     INCOMING: account6, , (imap) imap.gmail.com:993, SSL, passwordCleartext
     OUTGOING: , smtp.gmail.com:465, SSL, passwordCleartext, true

   account7:
     INCOMING: account7, , (pop3) pop.gmail.com:995, SSL, passwordCleartext
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

 Crash Reports
   http://crash-stats.mozilla.com/report/index/bp-5cc4aa15-5065-4e82-973d-f1dcf0170510 (5/10/2017)
   http://crash-stats.mozilla.com/report/index/bp-75468767-07fe-41d0-9c6d-ef7852170213 (2/13/2017)

 Extensions
   Lightning, 4.7.8, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.filesystem_reported: 1
     browser.cache.disk.smart_size_cached_value: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     dom.apps.reset-permissions: true
     extensions.lastAppVersion: 45.8.0
     font.internaluseonly.changed: false
     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
     gfx.crash-guard.glcontext.appVersion: 45.8.0
     gfx.crash-guard.glcontext.deviceID: 0x1049
     gfx.crash-guard.glcontext.driverVersion: 21.21.13.6909
     gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle: true
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle: true
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11: false
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp: false
     gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11: true
     gfx.crash-guard.status.glcontext: 2
     gfx.direct3d.last_used_feature_level_idx: 0
     mail.openMessageBehavior.version: 1
     mail.winsearch.firstRunDone: true
     mailnews.database.global.datastore.id: 5e68dded-9433-406a-9df2-21ce3b92968
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1493591745
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true
     print.printer_Canon_MX920_series_Printer.print_bgcolor: false
     print.printer_Canon_MX920_series_Printer.print_bgimages: false
     print.printer_Canon_MX920_series_Printer.print_duplex: -437918235
     print.printer_Canon_MX920_series_Printer.print_edge_bottom: 0
     print.printer_Canon_MX920_series_Printer.print_edge_left: 0
     print.printer_Canon_MX920_series_Printer.print_edge_right: 0
     print.printer_Canon_MX920_series_Printer.print_edge_top: 0
     print.printer_Canon_MX920_series_Printer.print_evenpages: true
     print.printer_Canon_MX920_series_Printer.print_footercenter:
     print.printer_Canon_MX920_series_Printer.print_footerleft: &PT
     print.printer_Canon_MX920_series_Printer.print_footerright: &D
     print.printer_Canon_MX920_series_Printer.print_headercenter:
     print.printer_Canon_MX920_series_Printer.print_headerleft: &T
     print.printer_Canon_MX920_series_Printer.print_headerright: &U
     print.printer_Canon_MX920_series_Printer.print_in_color: true
     print.printer_Canon_MX920_series_Printer.print_margin_bottom: 0.5
     print.printer_Canon_MX920_series_Printer.print_margin_left: 0.5
     print.printer_Canon_MX920_series_Printer.print_margin_right: 0.5
     print.printer_Canon_MX920_series_Printer.print_margin_top: 0.5
     print.printer_Canon_MX920_series_Printer.print_oddpages: true
     print.printer_Canon_MX920_series_Printer.print_orientation: 0
     print.printer_Canon_MX920_series_Printer.print_page_delay: 50
     print.printer_Canon_MX920_series_Printer.print_paper_data: 1
     print.printer_Canon_MX920_series_Printer.print_paper_height: 11.00
     print.printer_Canon_MX920_series_Printer.print_paper_name:
     print.printer_Canon_MX920_series_Printer.print_paper_size_type: 0
     print.printer_Canon_MX920_series_Printer.print_paper_size_unit: 0
     print.printer_Canon_MX920_series_Printer.print_paper_width: 8.50
     print.printer_Canon_MX920_series_Printer.print_resolution: -437918235
     print.printer_Canon_MX920_series_Printer.print_reversed: false
     print.printer_Canon_MX920_series_Printer.print_scaling: 0.70
     print.printer_Canon_MX920_series_Printer.print_shrink_to_fit: false
     print.printer_Canon_MX920_series_Printer.print_to_file: false

(Here is part 2)

print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_bottom: 0

     print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_left: 0
     print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_right: 0
     print.printer_Canon_MX920_series_Printer.print_unwriteable_margin_top: 0
     print.printer_HP_Officejet_Pro_6830.print_bgcolor: false
     print.printer_HP_Officejet_Pro_6830.print_bgimages: false
     print.printer_HP_Officejet_Pro_6830.print_colorspace:
     print.printer_HP_Officejet_Pro_6830.print_command:
     print.printer_HP_Officejet_Pro_6830.print_downloadfonts: false
     print.printer_HP_Officejet_Pro_6830.print_duplex: 1515870810
     print.printer_HP_Officejet_Pro_6830.print_edge_bottom: 0
     print.printer_HP_Officejet_Pro_6830.print_edge_left: 0
     print.printer_HP_Officejet_Pro_6830.print_edge_right: 0
     print.printer_HP_Officejet_Pro_6830.print_edge_top: 0
     print.printer_HP_Officejet_Pro_6830.print_evenpages: true
     print.printer_HP_Officejet_Pro_6830.print_footercenter:
     print.printer_HP_Officejet_Pro_6830.print_footerleft: &PT
     print.printer_HP_Officejet_Pro_6830.print_footerright: &D
     print.printer_HP_Officejet_Pro_6830.print_headercenter:
     print.printer_HP_Officejet_Pro_6830.print_headerleft: &T
     print.printer_HP_Officejet_Pro_6830.print_headerright: &U
     print.printer_HP_Officejet_Pro_6830.print_in_color: true
     print.printer_HP_Officejet_Pro_6830.print_margin_bottom: 0.5
     print.printer_HP_Officejet_Pro_6830.print_margin_left: 0.5
     print.printer_HP_Officejet_Pro_6830.print_margin_right: 0.5
     print.printer_HP_Officejet_Pro_6830.print_margin_top: 0.5
     print.printer_HP_Officejet_Pro_6830.print_oddpages: true
     print.printer_HP_Officejet_Pro_6830.print_orientation: 0
     print.printer_HP_Officejet_Pro_6830.print_page_delay: 50
     print.printer_HP_Officejet_Pro_6830.print_paper_data: 1
     print.printer_HP_Officejet_Pro_6830.print_paper_height: 11.00
     print.printer_HP_Officejet_Pro_6830.print_paper_name:
     print.printer_HP_Officejet_Pro_6830.print_paper_size_type: 0
     print.printer_HP_Officejet_Pro_6830.print_paper_size_unit: 0
     print.printer_HP_Officejet_Pro_6830.print_paper_width: 8.50
     print.printer_HP_Officejet_Pro_6830.print_plex_name:
     print.printer_HP_Officejet_Pro_6830.print_resolution: 1515870810
     print.printer_HP_Officejet_Pro_6830.print_resolution_name:
     print.printer_HP_Officejet_Pro_6830.print_reversed: false
     print.printer_HP_Officejet_Pro_6830.print_scaling: 1.00
     print.printer_HP_Officejet_Pro_6830.print_shrink_to_fit: true
     print.printer_HP_Officejet_Pro_6830.print_to_file: false
     print.printer_HP_Officejet_Pro_6830.print_unwriteable_margin_bottom: 0
     print.printer_HP_Officejet_Pro_6830.print_unwriteable_margin_left: 0
     print.printer_HP_Officejet_Pro_6830.print_unwriteable_margin_right: 0
     print.printer_HP_Officejet_Pro_6830.print_unwriteable_margin_top: 0

 Graphics

     Adapter Description: NVIDIA GeForce GT 620
     Vendor ID: 0x10de
     Device ID: 0x1049
     Adapter RAM: 1024
     Adapter Drivers: C:\WINDOWS\System32\DriverStore\FileRepository\nv_des

There are multiple Gmail accounts - which is the troubled one? An IMAP account or the POP one?

Wrt the IMAP accounts, it's recommended to set the 'Authentication type' to 'OAuth2' for both, the incoming and outgoing server.

Since Google made changes to the OAuth2 authentication recently you should also update to Thunderbird 52.1.0.

(Here is part 2)

In case you're being asked for the Troubleshooting Information again, the printer settings can usually be skipped, unless specifically being asked for.

Thank you so far for your help. Obviously I am not techno savvy at all. LoL

The one I am having trouble with is the first account listed when I bring up Thunderbird. I don't know how to set the Authentication type to OAuth2 but I will update to Thunderbird 52.1.0 as soon as I figure out how to do that.

OK I am Now updated to Thunderbird 52.1.0.

I don't know how to set the Authentication type to OAuth2

At the top right of the Thunderbird window, click the menu button > Options > Account Settings > Server Settings Choose 'OAuth2' from the 'Authentication method' drop-down menu.

Awesome! this worked! Thank you so much! Now I get to go through all the spam mail that was piling up. LOL