Host your own SMS/MMS Gateway on your Server. You can use it in your applications using API (C#, PHP etc.) provided with SMS Gateway. All the messages sent using the API will be stored on your server. It will also keep track of status of all the messages. You can also attach images to your messages.
Demo : https://rbsoft.org/downloads/sms-gateway/
Demo : https://rbsoft.org/downloads/sms-gateway/