FastMail.FM is now more secure for people whose browser support cookies (which includes nearly all modern browsers, including Internet Explorer, Netscape, Mozilla, Safari, Konqueror, and Opera). We strongly recommend that all FastMail.FM users do not turn off cookies in their browser. While FastMail.FM still works fine without cookies (just as it always has), the new security measures will not be active.
We now store your session id (the unique number identifying you after you log in) in a cookie, rather than sending it in the URL (the web page location). Storing it in the URL could cause problems, for instance if you copy and paste a URL into an email, it previously included the session id. These problems are avoided as long as you do not disable cookies in your browser.