Hi Jim, Could you check this out and see whether the information there can help you: https://support.mozilla.org/en-US/kb/switch-pop-imap-account

Thanks!

I had already read that link. Thanks anyway

My inference is that your Gmail account is POP and that you have the account set to keep all messages on server. I draw that conclusion because of the number of messages you have. You mention having moved messages to local folders. Are these 'moved' messages still in the Allmail folder in your online account? I ask that because moving doesn't necessarily mean that the messages are not still tied to the server. If they are, then you don't need to migrate, just create the account as IMAP.