My only access to the internet is email. How do I get GNOME?

If you are so disconnected from the internet that you only have email access, there are remailers out there that allow you to use FTP via email. Send a message with a body of help, with no quotes or punctuation to bitftp@pucc.princeton.edu or webmail.ucc.ie. It may be slow, but it will allow you to download GNOME tarballs via email. Check out http://www.csdl.tamu.edu/~cchung/cpsc689/ftpmail/ftpmtoc.html or http://www.cix.co.uk/~net-services/mrcool/stats.htm for an up to date list of available FTPMail sites.

The FTP sites you would be accessing through FTPMail are detailed above in "How do I get GNOME Tarballs", you would just use the FTPMail interface rather than directly FTPing to the site.