"All Mail" is the folder that Gmail keeps all your e-mail in. If you cleared "All Mail", that would do it!

Didn't clear All Mail or anything else Inbox mysteriously cleared and all items that were in the inbox were not in All Mail.

Drafts and Sent Mail were also cleared. Other folders apparently untouched.

Are all those folders empty when you look at them on your phone also?

If so, then "clearing deleted emails on my Samsung S4 (Aqua Mail)" probably was the cause. I believe that you accidentally cleared more than the deleted e-mails.

There is a possibility that you can recover the e-mails that Thunderbird previously cached, but it will depend on how much you have used Thunderbird since the "incident".

1. In Thunderbird, create a folder under "Local Folders" called "Recover". Then under the "Recover" folder, create a sub-folder called "Placeholder".

2. Find & open your Thunderbird Profile folder: Thunderbird menu: Help: Troubleshooting Information (If you cannot see the Thunderbird menu, press the Alt key or F10 key on your keyboard to show the menu) Under "Application Basics", beside "Profile Folder", click the "Show Profile" button. This will open a Windows Explorer window showing the contents of your Thunderbird Profile folder.

3. Keep that Windows Explorer window open, but quit Thunderbird.

4. Navigate in the Windows Explorer window to open the folder called "ImapMail", then the folder called "imap.gmail.com" under it. Maybe it won't be exactly "imap.gmail.com", but something like that.

5. In this folder you will see a variety of files. You will see "Inbox" and "Inbox.msf". Copy (not move), the "Inbox" file to your desktop. Do not copy the "Inbox.msf" file.

6. Double click on the "[Gmail].sbd" folder to open it. Copy (not move), the "All Mail", "Drafts", and "Sent Mail" folders to your desktop. Do not copy the files with .msf on the end.

7. In the Windows Explorer window, navigate back up and out of the "ImapMail" folder, and go to the "Mail" folder. Then the "Local Folders" folder under that. Then the "Recover.sbd" folder under that. (**profile folder**/Mail/Local Folders/Recover.sbd)

8. Move the files you put on the desktop to this folder (Inbox, All Mail, Drafts, Sent Mail).

9. Close Windows Explorer and start Thunderbird.

10. In Thunderbird, go to the "Recover" folder under "Local Folders", and see if your e-mails are there.

If this doesn't work, then the e-mails are gone for good.

Thanks, Bruce. I'll try to implement your suggestions tomorrow. I do have Inbox and Sent folders on my phone but was unaware that interactions could occur between phone and desktop.

There are no interactions for e-mail between your phone and your desktop. They both are reflecting what is on the e-mail server using IMAP.

If you delete an e-mail using the phone, the e-mail server will tell Thunderbird that the e-mail has been deleted, so it will also show that.

If you move an e-mail using Thunderbird from one IMAP folder to another (like from Inbox to a "folder" in Gmail called "Precious"), then the server will tell the phone that this happened, and the phone will show the same thing.

This is how you can use multiple devices to access the same e-mail, and they both show the same thing.