Building Bulk SMS Web Application

Question

We are creating a bulk SMS messages sending Web application using ASP.NET web Forms and C#. There could be multiple logged-in users, sending bulk (1-5000) messages to their clients.

As per initial R&D we have selected to use Twilio's SMS API for this purpose. But I am anxious about potential timeout issue while sending messages and saving response in loop, Also does Twilio accept multiple request instances?

Twilio has a limit or 1 message per second Then we can only send 3600 messages in one Hour, that would be a limitation.

Twilio provide Rest API but we are not familiar with MVC, so REST API idea has been dropped.

Please suggest other alternative, best practice and strategy to accomplish the task.

------------------UPDATE------------------------

Short Code Rest API Documentation

https://www.twilio.com/docs/api/rest/short-codes

Twilio Sending Documentation

https://www.twilio.com/docs/api/rest/sending-messages

Request Data From Twilio Documentation

https://www.twilio.com/docs/api/twiml/sms/twilio_request

Answer 1

With those volumes, there is no way you are going to be able to get by without using an SMS shortcode. Even if you could technically get it to work with a regular number, I suspect you would be shutdown as a spammer pumping out so many messages on a regular phone number.

A short code will let you send at at least 30 messages per second (1800/minute), and supposedly they can up that for you if you have a justified need.

https://www.twilio.com/sms/shortcodes

and this: https://www.twilio.com/help/faq/sms/can-my-twilio-sms-messages-be-blacklisted-as-spam

Can my Twilio SMS messages be blacklisted as spam?

Recipient carriers always reserve the right to filter out messages from certain numbers, and routinely do so to protect their users from spam.

If you’ll be sending SMS messages as part of a bulk campaign (with 30 or more identical or similar messages going out within a few minutes), we discourage you from using regular 10-digit numbers. Instead, we highly recommend using an SMS short code.