How to trace page behind the scene?

How to trace page behind the scene? And send all tracing information by emai开发者_开发问答l? not to show any tracing information on client side.

Sounds like you need to implement a custom trace listener, in this case an SMTP trace listener, a sample implementation can be found here:

http://www.codeproject.com/KB/trace/smtptracelistenerarticle.aspx

You could look into various logging frameworks for .NET. A popular one is log4net, which will allow you to keep track of any errors in your application and email you the logs. You can see a comparison chart of some logging frameworks here.