Why does Google require cookies to be enabled in order to use Gmail?
This is a very good question and to be honest, we don’t know. Certainly, Google could allow users access to Gmail without the necessity of cookies. However, by forcing users to enable cookies, they obtain a way to load/store user preferences in Gmail and a possible way to track email habits within your account to your PC. It is very likely that Google is storing all of your emails sent and received through the G-mail service, probably for advertiser usage in the future, as well as for statistics. However, what happens if Google decides to sell your email data to someone else? Do you own the data? In either case, by enabling cookies, they may obtain 1 more way to link your activity with your home PC. This is, of course, a best guess. Users should contact Google for exact details.
