Perish the thought … But if you lost access to the contents of your Gmail account, how bad would it be? Not a good day, but not so bad if you have a backup! I use getmail to backup all my Gmail messages to my home server.
0. Enable IMAP access to Gmail in Settings->Forwarding and POP/IMAP.
# deleting messages; (0) only print warnings and errors.
Getmail connects to the server and downloads any new messages into ~/mail/new/. When it runs the first time it may take a few minutes before it starts retrieving messages, and downloading the contents of All Mail may take several hours.