Outlook Retrieves Emails But Fails to Put Then Into the Inbox

I have a brand new Dell desktop that replaced a previous Dell desktop computer.  I have rebuilt everything on the new computer that was on the old, but have a very strange problem with Outlook.  When I click on "Send/Receive", I see at the bottom right of the screen that it is retrieving a bunch of emails from the Gmail server.  But upon completion of the retrieval, none of those emails appears in the Inbox.  If I click again on "Send/Receive", the process repeats.  And since I have set up retrieval to automatically issue the "Send/Receive" every three minutes, this process repeats and repeats, never placing the retrieved emails into the Inbox.  I should also comment that the count of the emails only increases, telling me that those emails do not disappear from the server.

I am using POP3, not IMAP.  I am using Outlook Classic, not the new Outlook.

I have been using Outlook for many, many years, and have successfully set up Outlook many, many times.  But I am totally baffled by what I am seeing.

I would appreciate any suggestions at all.

Thank you.

Len Jacobson