If you want to take back up in your Gmail it is impossible for you but it is very possible with Windows Live Email which creates the backup in itself. Sometime all the attachments will not be downloaded in such a situation you can use this Gmail Backup. It is excellent software which brings the all facilities to backup your entire Gmail account offline.
This software lets you download all the emails and attachments to your local machine. Another advantage of this software is you can download the latest emails which are not downloaded earlier in your computer. Know more software

Even more you can also specify the dates to back up the emails.This software prompts you to enable IMAP access in your Gmail account. This software is supposed to work with only Windows and Linux installed machines. [ Thank You ]