What was the possible solution that did not work?

I really don't remember which solutions I tried. I recently upgraded my Win 7 machine to Win 10 and everything went to hell. Eudora stopped working which is why I am trying to get Thunderbird to work. I'm hoping my next solution will work: I am getting a new computer with Win 7. Maybe then I can get Eudora to work.

Thanks for the reply.

It is time to give up on Eudora. Much as you may like it, it now sends mail that renders poorly in almost all mail situations. This is due to mail changing from ASCII to Unicode text. Eudora does not really understand Unicode at all. That is on top of the HTML issues

After Eudora came Eudora OSE. That was Thunderbird V3 with an add-on that was never updated. In my personal opinion Thunderbird V3 was about the worst version of Thunderbird ever released. it was flaky in many ways. So I do not recommend you go there, even if you can find a download.

So that leaves Thunderbird, as you have already installed it. The authentication method should be oAuth2.0, not password. As an old Eudora person that is something I think you might have changed from the default wizard settings. This is really a web authentication, but now the best way to make Gmail work. When you are working with a 100 ton elephant in the room you do not get much chance when it comes to an argument. You do it their way or the Highway.

Please add the troubleshooting information to your post so I can check the settings being used.

To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Use the button Copy to clipboard to select all. Do not check box "Include account names"!
• Paste this in your post.

While I am not all that happy with my Windows 10 upgrade, it does work very much like Windows 7 once you get used to it. As windows 7 will go end of life sooner than we would all like I feel that there is little choice but to change operating system. The only real question is to what. I chose the easy route, the free upgrade. I just take it as a blessing my son warned me off windows 8 before I inserted the DVD several years ago. If I had done that I would be using Linux now

Well, it looks like the one account which works (my own domain) uses password while the two gmail accounts which don't work use oAuth2.0.

here is the trouble shooting info:

 Application Basics

   Name: Thunderbird
   Version: 45.2.0
   User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20160630070546
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (imap) mail.flamingo-code.com:143, alwaysSTARTTLS, passwordCleartext
     OUTGOING: , mail.flamingo-code.com:587, alwaysSTARTTLS, passwordCleartext, true

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

   account6:
     INCOMING: account6, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

   account7:
     INCOMING: account7, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

 Crash Reports

 Extensions
   Lightning, 4.7.2, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}

 Important Modified Preferences

   Name: Value

     accessibility.lastLoadDate: 1469328245
     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: 45.2.0
     font.name.monospace.el: 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.x-cyrillic: Calibri
     font.name.sans-serif.x-unicode: Calibri
     font.name.sans-serif.x-western: Tahoma
     font.name.serif.el: 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.x-cyrillic: 14
     font.size.fixed.x-unicode: 14
     font.size.fixed.x-western: 14
     font.size.variable.el: 17
     font.size.variable.x-cyrillic: 17
     font.size.variable.x-unicode: 17
     font.size.variable.x-western: 18
     gfx.crash-guard.glcontext.appVersion: 45.2.0
     gfx.crash-guard.glcontext.deviceID: 0x0126
     gfx.crash-guard.glcontext.driverVersion: 9.17.10.4229
     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: c1f7c869-fea2-4cb5-b593-933bb96a4c4
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1469152670
     places.history.expiration.transient_current_max_pages: 104418
     plugin.importedState: true

 Graphics

     Adapter Description: Intel(R) HD Graphics 3000
     Vendor ID: 0x8086
     Device ID: 0x0126
     Adapter RAM: Unknown
     Adapter Drivers: igdumd64 igd10umd64 igd10umd64 igdumd32 igd10umd32 igd10umd32
     Driver Version: 9.17.10.4229
     Driver Date: 5-27-2015
     Adapter Description (GPU #2): NVIDIA Quadro 1000M
     Vendor ID (GPU #2): 0x10de
     Device ID (GPU #2): 0x0dfa
     Adapter RAM (GPU #2): 2048
     Adapter Drivers (GPU #2): nvd3dumx,nvwgf2umx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um,nvwgf2um
     Driver Version (GPU #2): 10.18.13.5362
     Driver Date (GPU #2): 7-22-2015
     Direct2D Enabled: false
     DirectWrite Enabled: false (10.0.10586.494)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 3000 Direct3D11 vs_5_0 ps_5_0) -- OpenGL ES 2.0 (ANGLE 2.1.0.316930d51ea9)
     GPU Accelerated Windows: 0

     AzureCanvasBackend: skia
     AzureSkiaAccelerated: 0
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: cairo

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 1
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.12
     4.12

     NSS
     3.21.1 Basic ECC
     3.21.1 Basic ECC

     NSS Util
     3.21.1
     3.21.1

     NSS SSL
     3.21.1 Basic ECC
     3.21.1 Basic ECC

     NSS S/MIME
     3.21.1 Basic ECC
     3.21.1 Basic ECC

OAuth2.0 uses cookies... just check they are allowed.

On the toolbar > Options > Privacy.

At this point make it Always and until they expire. as that is what is working for me.

When an attempt is made to authenticate with oauth2.0 a non Thunderbird dialog telling you that thunderbird would like access to your gmail appears and you must allow it.

The following is an example I saved long ago for the calendar when it started using oAuther 2.0.

Your alternative is to change the authentication method to password, but you need to allows less secure connections on the gmail web site. See https://support.google.com/accounts/answer/6010255?hl=en

If you use two factor authentication you will also need to generate an app password for Thunderbird. (that is why we recommend oAuth2.0.

There is also information here https://support.mozilla.org/en-US/kb/thunderbird-and-gmail I suggest you also click on the discuss beside the article. There is some good information there that has not made it into the main article.

Cookies are enabled.

I changed to Password and got the following:

SSL/TLS Password -> "could not parse command" STARTTLS Password -> connection to server timed out.

I'm giving up on this old laptop with Win 10. The hard drive has major problems. I am getting a new laptop with Win 7. I'll see how things go with the new computer.

Thanks for all your help.