If you are planning to back up your Gmail account using any of the programs listed below, you'll not be able do this. Gmail isn't able to permit IMAP access or third-party software as a default. Therefore, you'll need to alter some settings within Gmail to ensure an archive of your email. First thing you need to do is to permit IMAP access to your account. This can be done through Settings in the main interface to email. Then, from in the "Forwarding and POP/IMAP" section you can enable IMAP.