send email and sms to mass receivers using C++ or C# for Windows environment

I need help to write a C++ or C# in Windows environment to send out email and SMS message with attachment to mass receivers. There will be two files one contains the email address of receiver, and another contain the phone number of receivers and one file is to attach to the email and SMS message or send out the content of the file is ok. I also need this program to send out based on the pre-scheduled time of the day and which day of the week. The pre-scheduled time can be multiple times during the day.