Get Delivery Status from email sent using SendGrid API

Sometime when you send email to somebody, you want to know that the email sent or not right?

Sometime ago I use SendGrid for send email.

When using SendGrid for sending email, you can also add some custom variable that sent to your Event Listener file. So when receiver open that email or receive that email, you can have some variable that sent from that email to your Event Listener file. From that we can know the delivery status from email sent.

Let go to the practice.

First we need SendGrid account. You can register free in http://sendgrid.com/pricing.html.

When you already registered, then add some configuration to your environment using your SendGrid Username and Password.

ActionMailer::Base.smtp_settings = {
  :address => "smtp.sendgrid.net",
  :port => '25',
  :domain => [your_domain],
  :authentication => :plain,
  :user_name => [your_sendgrid_username],
  :password => [your_sendgrid_password]
}

Example

ActionMailer::Base.smtp_settings = {
  :address => "smtp.sendgrid.net",
  :port => '25',
  :domain => 'example.com',
  :authentication => :plain,
  :user_name => 'username',
  :password => 'password'
}

Now we need configure the email header. We need to download smtpapiheader.rb from http://wiki.sendgrid.com/doku.php?id=smtpapiheader.rb and save it to your model's folder.
On your mailer model.

class UserMailer < ActionMailer::Base

  require 'smtpapiheader.rb'

  def email(email)
    setup_email(email)
    @reply_to   = "#{email.user.first_name} #{email.user.last_name} <#{email.user.email}>"
    @from       = "#{email.user.first_name} #{email.user.last_name} "
    @subject    = "A letter from #{email.user.first_name}"
    content_type "text/html"
  end  

  protected
    def setup_email(email)
      hdr = SmtpApiHeader.new()
      receiver = email.email
      hdr.addTo(receiver)
      hdr.setUniqueArgs({:key => email.key})

      header = hdr.asJSON()
      
      @recipients  = "#{email.email}"
      @sent_on     = Time.now
      @headers["X-SMTPAPI"] = header
    end

end

Now we need to create Event Listener file.
create some controller on your rails application.
I use email controller for this example.

class EmailController < ApplicationController

  def receive_email_notification
    if !params.blank? and !params[:key].blank? and !params[:email].blank? and !params[:event].blank?
      email = Email.find_by_email_and_key(params[:email], params[:key])
      if email
        case params[:event]
        when "open"
          #add some logic when the listener receive notification
          email.update_attribute(:send_status, params[:event])
        when "click"
          email.update_attribute(:send_status, params[:event])
        when "unsubscribe"
          email.update_attribute(:send_status, params[:event])
        when "bounce"
          email.update_attribute(:send_status, params[:event])
        when "spamreport"
          email.update_attribute(:send_status, params[:event])
        end
      end
      @email = email
    end
    redirect_to :root unless email
  end

end

Now add some line to your config/routes.rb

  map.resources :emails,:collection => {:receive_email_notification => :post }

Now we need SendGrid to know the url our Event Listener. We need to log on to SendGrid.
On Home -> Developers -> Post Event URL (http://sendgrid.com/developer/postEventUrl).
On that page you can submit your url.
Example : http://example.com/emails/receive_email_notification

That's it. For more info about SendGrid http://sendgrid.com, for SendGrid API http://wiki.sendgrid.com/.