I tried my all hit and trial but unable to pass EmailId in web service url but at last.
I got alternative solution for above problem.But if some on have any another solution for it then please help me.That answer will be acceptable.
Alternative solution.
[OperationContract()]
[WebGet(UriTemplate = "/myservice/{username}?v={email}", ResponseFormat = WebMessageFormat.Json)]
string myservice(string username,string email);