I'm having trouble taking the contents of TBird and IMAP-ing it to a Gmail account (~60,000 messages). I have added the Gmail account as per the instructions on these forums including Advanced Config for IMAP and OAuth2, but no messages appear in GMail. Am I missing something obvious? Do both accounts have to be the same UserID? I don't want to mistakenly transfer the contents of an empty GMail account to the TBird account wiping out 20 years of messages. (I do have exports of all messages, btw) I'd be very grateful for any breadcrumbs that point me in the right direction. Thank you in advance. aj