Only about a year. I still dont use it that much, only for signups such as myspace, facebook etc...but its great. I really should use it more.
3 and a half years old. May 2004 Gmail was announced on April 1, 2004 and the first accounts began their trials on March 21. back then you only got 5 invites but you had to have used your account for a few weeks before you got the invites to send. later you got 10 invites, and they reset the 10 when you used them up, and then it was changed to 50 the filter at the start time was limited to about 20 words. there was no google talk
My First email is one from Ebay (i must have deleted earlier ones) telling me about my change of email address on my account. This was sent February 21st, 2005 1:42pm.