No. of Recommendations: 9
Your data, if you use Google, is not your data. I can't be any more blunt than that.
A little worse than that, actually.
Even if you eschew the Google products yourself, all emails you exchange with people using gmail get mined. I conservatively assume they create a profile for your email address from that content, even if it is "anonymized" [ha] or denied.
Last I heard, all messages are kept forever. "Deleting" them just hides them from the gmail user interface.
Jim
(used to do work in "anonymous" user profiling for a search engine company...we ran sweepstakes contests to get real name/address/email tuples to train with, and joined those to commercially available demographic profiles by name/address)