Outgoing Emails

HTTP Server → Queue → Email Worker → Gmail API → DB

Incoming Emails

IMAP Worker → Queue ↓ Label Assigner ↓ Tagged Queue ↓

Storage Worker ↓

PostgreSQL Elasticsearch

FLOW 1 — Outgoing Emails (HTTP Server → Queue → Worker → Gmail API)

1. HTTP Server

• User sends an email from your app.
• Server pushes the email request into a queue (Rabbitmq).
• This ensures:
  • High throughput
  • Durability
  • No blocking of HTTP request
  • Retry logic independent of API failures

2. Worker (Email Sender Worker)

This worker does 3 things:

a) Consume message from queue

• Reads the queued email event.
• Does not lose the event because:
  • ACK only after Gmail API success
  • Retry + DLQ if failing

b) Store the email body & metadata into DB

• Before sending, it stores:
  • from, to
  • subject
  • HTML body
  • attachments (optional)
  • status = "PENDING"
  • timestamp