My wife has used Thunderbird set to POP3 with her Gmail account for many years. She leaves messages on the Gmail server after she pops and sorts her mail in Thunderbird. Access began failing on June 7 with bad password message. After adding Oath2.0 for Gmail login, access was restored, but Thundebird began downloading all of her messages, from 2012 onward! She wants a fix that will pick up where she left off. I use Thunderbird with an account from my local internet provider, but not with Gmail, so I am less able to help her. Any suggestions? She will not delete the old mail on Gmail. Thank you, Steve Johnson