to my knowledge there are 1500 servers
Any email address you already have will do. If you don't have one, you can create an email account for free on many different servers, for example GMail, Yahoo, Hotmail, etc.
Some options include Yahoo Google/Gmail AOL MSN/Hotmail Mac/Me Verizon AT&T SBC Global I personally have had Gmail & Hotmail, and don't like Gmail although many people have it. I LOVE Hotmail.
Outlook provides connection to E-mail servers/services. (these can come from many different providers... from Hotmail, Gmail, Yahoo; or corporate services like Microsoft Office365, Exchange servers, Amazon services, Google corporate services, etc...)
Gmail is actually better than Yahoo Mail. But, Yahoo Messenger (Yahoo Chat) is better than Google Talk (Gmail Chat). I personally like to use Yahoo!because of its simlicity. It is also better known. And yes, the yahoo Chat is better than Gmails. Google also is too high of an over acheiver. It has too many things coming out.
56 google servers are in india but if only server that would be 5
2.5 Lakhs approx i think
Yes you need an email ID for that too. However Gmail is not necessary to receive mails. You can get mails to Yahoo mail or hotmail too.
100 million
Gmail has almost all of the same features, less ads, and more features. Gmail also comes with a Blogger account, YouTube account, Orkut (social network) account, and many others.
You could forward your Yahoo mail to another webmail account that you can access (AOL, Gmail, Hotmail and many others). In this way you can get your mail without having to go to yahoo.
You could try Google Mail (GMail), Yahoo! Mail, MSN (Hotmail). There are many more