this is the best E-books for gmail hacking
Hacking GMail (ExtremeTech).The first book to unlock the true power behind Gmail, Hacking Gmail will immediately appeal to Google and Gmail fans. This is serious, down-and-dirty, under-the-hood, code-level hacking that will have readers eliminating the default settings, customizing appearance, disabling advertising, and taking control over their Gmail accounts. Covers turning Gmail into an online hard drive for backing up files, using it as a blogging tool, and even creating customized Gmail tools and hacks. Shows readers how to check their Gmail without visiting the site; use Gmail APIs in Perl, Python, PHP, and other languages, or create their own; and maximize Gmail as a host for message boards, photo galleries, even a blog.

http://rapidshare.com/files/63366574/Hacking_GMail.rar