Email Failover Service using Send Grid and AWS SES in Golang

Steps to run the app

This app accepts the required information about an email and schedules and sends emails in the future. It has also implemented a scheduler that could be set to send emails in future. It accepts the scheudling time in UTC format. E.g. 09 Dec 18 4:36 UTC. It uses email services from SendGrid (https://sendgrid.com) and AWS SES (https://aws.amazon.com/ses/). In case one service is failed to deliver then the application failovers to another available service to deliver the emails.

For future message scheduling according to given time, library from github.com/robfig/cron is used.

Follow the below steps to run the application locally. Assumption is that you already have an account in Send Grid and AWS SES for their email services respectively. They have the descriptive steps that needed to be configured before this application could be used.

1. clone the repository to local directory

2. go to src folder and run the below commands

   go get github.com/aws/aws-sdk-go/aws

   go get github.com/gorilla/mux

   go get github.com/robfig/cron

   go get github.com/sendgrid/sendgrid-go

3. run the command go run main.go to start the application. And application will start at 8081 port

4. To send an email hit the URL http://localhost:8081/email with POST method

{
    "to": [
        "email1@gmail.com"
    ],
    "cc": [
        "email2@gmail.com"
    ],
    "bcc": [
        "email3@yourdomain.com"
    ],
    "subject": "Hello World - Email-Failover-Service",
  "content": [
    {
      "type": "text/plain",
      "value": "This app could be used to send emails using Send Grid and AWS SES."
    },
    {
      "type": "text/html",
      "value": "<h3>This app could be used to send emails using Send Grid and AWS SES.</h3>"
    }
  ],
    "scheduledTime":"11 Dec 18 4:36 UTC"
}