Forwarding SMS Messages to Email Using Ruby

Businesses get communications through many channels. It can be handy to have a searchable archive of messages in one place. Forwarding SMS messages to email lets you keep both kinds of messages in one spot. Plivo makes it easy to forward SMS messages to email using the most popular web development languages. Here we walk through the process with Ruby.

Prerequisites

To get started, you need a Plivo account — sign up with your work email address if you don’t have one already. To receive incoming messages, you must have a Plivo phone number that supports SMS; you can rent numbers from the Numbers page of the Plivo console or by using the Numbers API. If this is your first time using Plivo APIs, follow our instructions to set up a Ruby development environment. Be sure to install the Mail library.

Create a Rails controller

Change to the project directory and run this command to create a Rails controller.

$ rails generate controller Plivo email

This command generates a controller named plivo_controller in the app/controllers/ directory and a respective view in app/views/plivo directory. We can delete the view as don’t need it.

$ rm app/views/plivo/email.html.erb

Create the forward SMS application

Edit app/controllers/plivo_controller.rb and paste into it this code.

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require 'mail'

class PlivoController < ApplicationController
def email()
    # The phone number of the person who sent the SMS
    from_number = params[:From]
    # The Plivo number that received the SMS
    to_number = params[:To]
    # The text that was received
    text = params[:Text]

    # Print the message
    puts "Message received from #{from_number}: #{to_number}: #{text}"
    forward_email(text, from_number)
end

def forward_email(text, from_number)
    options = {
        :address              => "smtp.gmail.com",
        :port                 => 587,
        :user_name            => '<email_address>',
        :password             => '<email_password>',
        :authentication       => 'plain',
        :enable_starttls_auto => true
    }

    Mail.defaults do
        delivery_method :smtp, options
    end
    
    Mail.deliver do
        to '<recipient_email_address>'
        from '<from_email_address>'
        subject "SMS from #{from_number}"
        body text
    end
end
end
Note: If you use Gmail to send email, you must use an app password, which will be treated as your password to send email from the application.

Save the file and start the Rails server.

$ rails server

You should see your basic server application in action at http://localhost:3000/plivo/email/.

Set up ngrok to expose your local server to the internet.

Note: For ngrok testing, add this line to config/environments/development.rb.
config.hosts << /[a-z0-9-]+\.ngrok\.io/

Create a Plivo application

Associate the controller you created with Plivo by creating a Plivo application. Visit Messaging > Applications and click Add New Application. You can also use Plivo’s Application API.

Give your application a name — we called ours Email SMS. Enter the server URL you want to use (for example https://<yourdomain>.com/email_sms/) in the Message URL field and set the method to POST. Click Create Application to save your application.

Create Application

Assign a Plivo number to your application

Navigate to the Numbers page and select the phone number you want to use for this application.

From the Application Type drop-down, select XML Application.

From the Plivo Application drop-down, select Email SMS (the name we gave the application).

Click Update Number to save.

Assign Application

Test

Send a text message to the Plivo number you associated with the application using a regular mobile phone. The incoming message should be forwarded to the email address you specified.