Here is a quick Hotmail trick: you can check the exact date on which you opened a Hotmail account (which typically is also the date at which you started using a particular email address). This start date is available for all Windows Live Hotmail accounts, whether your email address ends in "hotmail.com", "live.com", or a Hotmail or Windows Live email address with a specific country code instead of ".com".
Follow these steps to check since when you have been a Hotmail user / Windows Live user:



And this is a nifty trick to keep in mind if you ever want to know since when you have been a Hotmail member.
Hotmail Tip: If you want to know since when you have been a Hotmail Plus subscriber, just scroll down on that same page until you see the section labeled "Windows Live Hotmail Plus options", and click on the "Billing management" link. A new window will open to Microsoft Billing: at the very bottom of that page, you will see a listing of all paid Windows Live and Microsoft services you have ever used under this particular Windows Live ID (your Hotmail email address). Click on the "Windows Live Hotmail Plus" link closest to the bottom of the page (i.e., the oldest) under "Your Services", and you will see a timestamped entry for the billing cycle in question: