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.

Thanks for taking a look. hope you can see something that will help. N.G.

 Application Basics

   Name: Thunderbird
   Version: 52.1.1
   User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:52.0) Gecko/20100101 Thunderbird/52.1.1
   Profile Folder: Show in Finder
   Application Build ID: 20170509142926
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory
   Profiles: about:profiles

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

 Crash Reports

 Extensions
   Lightning, 5.4.1.1, 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
     extensions.lastAppVersion: 52.1.1
     font.internaluseonly.changed: true
     mail.openMessageBehavior.version: 1
     mail.spotlight.firstRunDone: true
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     mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     mailnews.database.global.views.global.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     media.gmp.storage.version.observed: 1
     network.cookie.cookieBehavior: 3
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
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     security.default_personal_cert: Select Automatically
     security.sandbox.content.tempDirSuffix: {ae493594-1c57-224b-a4a9-5cde3dae94da}

 Graphics

     GPU #1
     Vendor ID: 0x8086
     Device ID: 0x0126

     Features
     WebGL Renderer: Intel Inc. -- Intel HD Graphics 3000 OpenGL Engine -- 2.1 INTEL-10.0.51

     AzureCanvasBackend: skia
     AzureCanvasAccelerated: 0
     AzureFallbackCanvasBackend: none
     AzureContentBackend: skia
     TileHeight: 512
     TileWidth: 512

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.13.1
     4.13.1

     NSS
     3.28.4
     3.28.4

     NSS Util
     3.28.4
     3.28.4

     NSS SSL
     3.28.4
     3.28.4

     NSS S/MIME
     3.28.4
     3.28.4

For both of your Gmail account, go to your account settings, and set the 'Authentication type' to 'OAuth2'. This goes for both, incoming server (IMAP), and outgoing server (SMTP).

thank you much. I will give it a try. do I need to do this for the SMTP? I don't see an option in the outgoing server menu. NG

Go to Tools|Account Settings

The last account in the list is "Outgoing Server (SMTP)". Select this.

At the right, a list of your SMTP servers appears. Select the one you want to edit, click the "Edit" button.

At this point you'll be glad that you have given all your SMTP servers distinctive names.

Christ1, I figured out how to set the outgoing server as well but now I am only getting incoming mail on my main gmail account and every time I open mail a pop up from mozillza comes on and asks for authentication using my password. Can you help get me back to a normal functioning? Maybe the outgoing mail SMTP is messed up and I don't think I have given all the outgoing SMTPs distinct names. There are two listed. One is gmail and the other is googlemail. But only one is set as the default for all accounts.

christ1, Is there a way I can just disable the second account but keep the messages I have saved there? It is an account from American University of Afghanistan (@auaf.edu.af) It is not working now as I don't seem to have the right password and now every time I open T-bird a credential screen form T-bird pops up. I am trying to get my last password from the university but I don't work there anymore and the mail should be shut down and they may not give me any support. Hope you can help me out on this one as these credential screens seem to be interfering with my outgoing mail for my gmail account too. thanks

Unfortunately, Thunderbird doesn't have a simple mechanism to enable or disable an account.

If Thunderbird allows you to see the messages in the defunct account, you could just copy or move them to a folder under the Local Folders account.

If there are a very large number of messages, or there is a complex folder structure, then another approach is to move its data files. Start by creating, in Thunderbird, a new sub-folder under Local Folders. Give it a distinctive name.

Open the defunct account's settings and note the pathname stored under Server Settings|Local directory:.

Open Thunderbird's profile in your file manager. One way to do this is to go to Help|Troubleshooting Information and click the button near the top labelled Profile folder. This should open the profile in your file manager ("Finder"?)

Now close Thunderbird.

Now you can locate the defunct account's data, browsing to the "Local directory:" pathname you noted earlier, and, still in your file manager, copy its contents to the new subfolder you created under Local Folders. This will have the distinctive name you gave it, with an .sbd extension.

When you re-start Thunderbird, it should show the old data under Local Folders. When you're happy that it has retained all you want to keep, you can remove the defunct account.

It goes without saying that making a backup of your profile before you start is a good insurance against any accidents, so you can revert to where you are now.

Oh, and all of this assumes that your Local Folders and the defunct account use the same underlying storage structure. By default, they will both use the mbox system. Thunderbird also has an experimental implementation of maildir, but you can't transplant mbox to maildir or vice versa.

You may post your Troubleshooting information again, so we can verify the changes you made are correct.

Also a screenshot of the popup may help. https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

Application Basics

   Name: Thunderbird
   Version: 52.1.1
   User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:52.0) Gecko/20100101 Thunderbird/52.1.1
   Profile Folder: Show in Finder
   Application Build ID: 20170509142926
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory
   Profiles: about:profiles

 Mail and News Accounts
   account1:
     INCOMING: account1, , (imap) imap.googlemail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

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

   account3:
     INCOMING: account3, , (imap) imap.googlemail.com:993, SSL, OAuth2
     OUTGOING: , smtp.googlemail.com:465, SSL, passwordCleartext, true

 Crash Reports

 Extensions
   Lightning, 5.4.1.1, 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
     extensions.lastAppVersion: 52.1.1
     font.internaluseonly.changed: false
     mail.openMessageBehavior.version: 1
     mail.spotlight.firstRunDone: true
     mailnews.database.global.datastore.id: 1b064ab4-48f3-8440-8a34-d55828d5d30
     mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     mailnews.database.global.views.global.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     media.gmp.storage.version.observed: 1
     network.cookie.cookieBehavior: 3
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1495638458
     places.history.expiration.transient_current_max_pages: 64727
     plugin.importedState: true
     print.macosx.pagesetup-2: PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4KPCFET0NUWVBFIHBsaXN0IFBVQkxJQyAiLS8vQXBwbGUvL0RURCBQTElTVCAxLjAvL0VO…
     security.default_personal_cert: Select Automatically
     security.sandbox.content.tempDirSuffix: {ae493594-1c57-224b-a4a9-5cde3dae94da}

 Graphics

     GPU #1
     Vendor ID: 0x8086
     Device ID: 0x0126

     Features
     WebGL Renderer: Intel Inc. -- Intel HD Graphics 3000 OpenGL Engine -- 2.1 INTEL-10.0.51

     AzureCanvasBackend: skia
     AzureCanvasAccelerated: 0
     AzureFallbackCanvasBackend: none
     AzureContentBackend: skia
     TileHeight: 512
     TileWidth: 512

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.13.1
     4.13.1

     NSS
     3.28.4
     3.28.4

     NSS Util
     3.28.4
     3.28.4

     NSS SSL
     3.28.4
     3.28.4

     NSS S/MIME
     3.28.4
     3.28.4

account3: OUTGOING: , smtp.googlemail.com:465, SSL, passwordCleartext, true

Authentication type should be set to OAuth2, just as for account1.

now I am only getting incoming mail on my main gmail account and every time I open mail a pop up from mozillza comes on and asks for authentication using my password.

You'll have to go through the authentication once, and give permission for Thunderbird to access your Gmail account. This is how it works.

to christ1 I hope you get this. I know it has been about 10 days since I replied last. Sorry for the delay, but you have really been helpful.

First, I am not familiar with going through the authentication process. Can you tell where to start? Second, I can't get my password from American University (one of the imap accounts) and that seems to be stopping the gmail. If I just "remove account" under settings will anything be preserved. I have a lot of messages logged under this account. Will contacts be saved?

First, I am not familiar with going through the authentication process.

You'll be prompted for everything needed.

I can't get my password from American University (one of the imap accounts)

You'll need to work with the University IT folks to recover your password.

If I just "remove account" under settings

I'm not sure what you're trying to achieve by removing the account. You'd still need to have the password if you want to re-create the account later.

OK< I got the password and that corrected the error messages from google. Now the University will shut this account down as I don't work there any longer. If I remove the account from Thunderbird how do I save my contacts and some of the messages. I understand I can put some messages in the local folder. Do you know where in the Mac library my contacts and messages are stored and how to get there?

Contacts are independent from email accounts, so you'd not loose any contacts in your local address books when removing an account.

Wrt messages in your IMAP account, you'd need to move messages you want to keep off of the server to your 'Local Folders' account. You may want to recreate any existing folder structure on the server underneath 'Local Folders'. To move messages, select the messages to be moved - right-click a selected message - Move To. If it's a large number of messages to be moved, don't do everything at once, do it in batches. Note, that Google may throttle mass transactions, so take your time.

All messages and contacts are stored in your local Thunderbird profile folder. http://kb.mozillazine.org/Profile_folder_-_Thunderbird