Gmail stores all your emails in the 'All Mail' folder. Many people do not subscribe to see that folder because it is a duplicate of everything thus doubling the size of your profile folder. If you delete anything from the 'All Mail' folder then it will delete that email from whatever other folder it appears in because it does not exist on server.

To unsubscribe: In Folder Pane:

• right click on the 'imap gmail name of account' - usually an email address - folder and select 'Subscribe' from drop down list.
• Click on 'Refresh'
• Select the 'All Mail' folder
• click on 'Unsubscribe'
• click on 'OK'

Gmail understands that it's not helpful to display everything, sent and received and archived in one folder, so they invented 'labels' which acts like a tag, thus enabling the display of an email in any folder that has the same tag. In effect this means you can display the same email in more than one folder. Thunderbird has no concept of 'labels', so it downloads whatever is displayed in the various 'folders' aka 'labels' and displays them in the Imap folders of same name.

In the gmail webmail account, in settings > labels, you can select options to 'Show in imap' for any folder. The 'Inbox' is selected by default, but it might be helpful to uncheck some options such as 'All Mail' folder. I've included an image which shows how I've selected some folders to 'show in imap' and unchecked others.

Imap accounts can only display whatever is on the server, so first please logon to gmail webmail account and find out what has been put into the server Inbox. Are the new emails displaying in the webmail account Inbox? Then select the 'All Mail' folder to see what 'labels' have been applied' I've included another image which shows some contents of my gmail webmail 'All Mail' folder - I've highlighted what something with/without labels looks like. If no label, gmail has 'archived' it, so it only displays in the 'All Mail' folder. Personally, I do not find that convenient, so I created my own 'Archives' folder, so I can sort my archived stuff into a separate folder - much easier to find and I do not need to see the 'All MAil' folder. Did you find new emails with no label or did they have another label like 'Important' etc ?

Wow. Thanks so much! Had no idea it worked quite like that, but what really mystifies me is before yesterday everything was showing up in both Inbox and All Mail. But yesterday mail stopped going to Inbox. I changed the label page as you note, and now NEW mail gets the label "Inbox". I had to go and change the interim email labels to Inbox to see them in TBird. No idea how the inbox labeling changed for those 2 days. Thanks again!