Proofpoint Mock API

Rationale

We have an application that previously sent emails using SendGrid. For local development and testing, we relied on Docker images that mock SendGrid (e.g. ghashange/sendgrid-mock) to capture and inspect emails without sending them externally.

A new requirement mandated migration from SendGrid to Proofpoint Secure Email Relay. At the time of writing, no equivalent mocking solution exists for Proofpoint that provides the same local email sending & receiving functionality as sendgrid-mock. This gap created the need for the code in this repository.

Components

• custom api: mocks Proofpoint's send api endpoint and sends an email with smtp
• Nodemailer: smtp client
• Mailhog: fake smtp server

Build the proofpoint mock api

pnpm clean && pnpm install && pnpm build
docker compose build --no-cache

Usage (local development)

Starts the fake smtp server and the mock api:

pnpm dev

Send a PUT request to the /send api endpoint e.g.

curl --location 'http://localhost:3000/send' \
--header 'Content-Type: application/json' \
--data-raw '{
  "content": [
    {
      "body": "Simple test message from SER!",
      "type": "text/html"
    }
  ],
  "from": {
    "email": "[email protected]"
  },
  "headers": {
    "from": {
      "email": "[email protected]"
    }
  },
  "subject": "Test Subject from SER!",
  "tos": [
    {
      "email": "[email protected]",
      "name": "YOUR NAME"
    }
  ]
}'

Usage (docker compose)

1. Add the following to docker-compose:
   1. Select a smtp service (e.g. mailhog) and configure it
   2. Configure the proofpoint-mock service

       smtp:
         image: mailhog/mailhog:v1.0.1
         container_name: smtp_server_dev
         restart: unless-stopped
         ports:
           - "1025:1025"   # SMTP
           - "8025:8025"   # Web UI
   
       proofpoint:
         container_name: proofpoint_dev
         image: ghcr.io/eresearchqut/proofpoint-mock:publish_docker
         environment:
           - PORT=3000
           - SMTP_HOST=smtp
           - SMTP_PORT=1025
         depends_on:
           - smtp
         ports:
           - "7002:3000"
   

2. Check emails: http://localhost:8025