Inbound Email

[DevCEDTeam]

flowchart TD
    A[Inbound Email Received] --> B[MX Records Process via Cloudflare]
    B --> C[Cloudflare Worker Routes Email]
    C --> D[Google Cloud Function Handles Email]

    D --> E1[Bounce Management via IMAP]
    D --> E2[Open Tracking with Pixel]
    D --> E3[Unsubscribe Handling via Link]

    E1 --> F1[Store Bounce Data in Firestore/MongoDB]
    E2 --> F2[Store Open Tracking Data in Firestore/MongoDB]
    E3 --> F3[Store Unsubscribe Data in Firestore/MongoDB]

    D --> G[Send Email Out via OAuth 2.0]

    G --> H[User Interactions]
    H --> |Bounce| F1
    H --> |Open| F2
    H --> |Unsubscribe| F3

[DevCEDTeam]

To provide step-by-step Gilbert instructions based on your screenshots and detailed flowchart analysis, we'll proceed with a clear and structured plan.

I'll describe how to integrate the bounce management, email open tracking, and unsubscribe handling using the available GCP, Firebase, and Cloudflare infrastructure while ensuring OAuth 2.0 authentication is properly configured for email sending.

Step-by-Step Gilbert Instructions: Email Management System

1. Infrastructure Setup (GCP & Cloudflare)

Step 1: Configure Google Cloud Infrastructure Using Terraform

• Install Terraform if not already installed:

  brew install terraform

• Create a main.tf file for setting up a VPC, Cloud Functions, Firestore, and Storage bucket:

  provider "google" {
  credentials = file("path/to/your-service-account.json")
  project     = "gmail-bulk-sending"
  region      = "us-central1"
  }
  
  resource "google_compute_network" "vpc_network" {
  name = "vpc-email-management"
  }
  
  resource "google_cloudfunctions_function" "email_function" {
  name        = "processEmailFunction"
  runtime     = "python39"
  entry_point = "process_email"
  trigger_http = true
  source_archive_bucket = google_storage_bucket.email_function_bucket.name
  source_archive_object = "email_function.zip"
  available_memory_mb = 256
  }
  
  resource "google_storage_bucket" "email_function_bucket" {
  name = "email-function-bucket-${var.project_id}"
  location = var.region
  force_destroy = true
  }

• Initialize and Apply the Terraform Configuration:

  terraform init
  terraform apply

Step 2: Set Up MX Records in Cloudflare

• Log into your Cloudflare dashboard and configure MX records for inbound emails:

  • route1.mx.cloudflare.net (Priority: 2)
  • route2.mx.cloudflare.net (Priority: 81)
  • route3.mx.cloudflare.net (Priority: 91)

Step 3: Create a Cloudflare Worker

• Create a Worker Script for routing emails through Cloudflare to your Google Cloud Function:

  addEventListener('fetch', event => {
    event.respondWith(handleRequest(event.request))
  })
  
  async function handleRequest(request) {
    const emailRecipient = request.headers.get('To')
    const response = await fetch('https://REGION-gmail-bulk-sending.cloudfunctions.net/processEmailFunction', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ email_content: await request.text() })
    })
    return new Response(response.body, {
        status: response.status,
        headers: response.headers
    })
  }

• Deploy this worker script using Cloudflare's dashboard or Terraform.

Step 4: Configure OAuth 2.0 for Sending Emails

• In the Google Cloud Console, under the API & Services -> Credentials page (as shown in your screenshots), set up the OAuth 2.0 client for email sending via Gmail.

  • Client ID: 895054114655-75saopm0mheadp8hdm3nqnbsi4c7so7k.apps.googleusercontent.com
  • API Key: AIzaSyCx2S2YKYBiAKcUwEYJqeK9yfL7PPpxHq4

Step 5: Configure Firestore/MongoDB for Email Metadata Storage

• In your Google Cloud project, set up Firestore or use MongoDB (if you prefer) for storing email metadata like bounces, opens, and unsubscribes.

  • To install Firestore:

    gcloud firestore databases create --region=us-central1

2. Email Bounce Management

• Python Script to Monitor Bounced Emails via IMAP:

  import imaplib
  import email
  from pymongo import MongoClient
  
  client = MongoClient("mongodb://localhost:27017/")
  db = client.email_db
  
  imap_server = "imap.gmail.com"
  user = "you@gmail.com"
  password = "yourpassword"
  
  mail = imaplib.IMAP4_SSL(imap_server)
  mail.login(user, password)
  mail.select("inbox")
  
  status, messages = mail.search(None, '(FROM "mailer-daemon")')
  mail_ids = messages[0].split()
  
  for mail_id in mail_ids:
    status, msg_data = mail.fetch(mail_id, "(RFC822)")
    for response_part in msg_data:
        if isinstance(response_part, tuple):
            msg = email.message_from_bytes(response_part[1])
            subject = msg["subject"]
            body = msg.get_payload(decode=True)
            db.bounced_emails.insert_one({"subject": subject, "body": body})
  
  mail.logout()

3. Email Open Tracking with a Pixel

• Python Script for Sending Emails with a Pixel:

  import smtplib
  from email.mime.multipart import MIMEMultipart
  from email.mime.text import MIMEText
  
  def send_email(to_email):
    msg = MIMEMultipart("alternative")
    msg["From"] = "you@gmail.com"
    msg["To"] = to_email
    msg["Subject"] = "Your Subject"
  
    html = """<html><body>
    <p>Welcome to our newsletter!</p>
    <img src="https://yourserver.com/pixel.png?email={}"/>
    </body></html>""".format(to_email)
  
    msg.attach(MIMEText(html, "html"))
  
    server = smtplib.SMTP("smtp.gmail.com", 587)
    server.starttls()
    server.login("you@gmail.com", "yourpassword")
    server.sendmail("you@gmail.com", to_email, msg.as_string())
    server.quit()
  
  send_email("recipient@example.com")

• Server-Side Pixel Tracking Script:

  from flask import Flask, request
  
  app = Flask(__name__)
  
  @app.route("/pixel.png", methods=["GET"])
  def track_open():
    email = request.args.get("email")
    print(f"Email opened by: {email}")
    return "", 200
  
  if __name__ == "__main__":
    app.run(debug=True)

4. Unsubscribe Handling

• Python Script for Sending Emails with an Unsubscribe Link:

  def send_email_with_unsubscribe(to_email):
    msg = MIMEMultipart("alternative")
    msg["From"] = "you@gmail.com"
    msg["To"] = to_email
    msg["Subject"] = "Unsubscribe from our mailing list"
  
    html = """<html><body>
    <p>If you wish to unsubscribe, click <a href="https://yourserver.com/unsubscribe?email={}">here</a>.</p>
    </body></html>""".format(to_email)
  
    msg.attach(MIMEText(html, "html"))
  
    server = smtplib.SMTP("smtp.gmail.com", 587)
    server.starttls()
    server.login("you@gmail.com", "yourpassword")
    server.sendmail("you@gmail.com", to_email, msg.as_string())
    server.quit()
  
  send_email_with_unsubscribe("recipient@example.com")

• Flask Server for Unsubscribe Handling:

  @app.route("/unsubscribe", methods=["GET"])
  def unsubscribe():
    email = request.args.get("email")
    print(f"Unsubscribed: {email}")
    return "You have been unsubscribed."

5. Test the System

• Bounce Testing: Send emails to invalid addresses and ensure the bounce script works.
• Open Tracking Testing: Open tracked emails and verify the pixel is triggered.
• Unsubscribe Testing: Click unsubscribe links and ensure the Flask server logs the unsubscribes.

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Let me know if you'd like additional examples or clarification!