reference from below link:
http://aspsolutionkirit.blogspot.in/2014/03/send-text-or-bulk-sms-in-aspnet-using-c.html
followed below steps
registered with site2sms
and register at mashape.com and used generated key …but error message show Invaild mashape key
아래에 의견을 추가하고 토론에 참여하세요.