Email Validator Architecture

System Overview

FastAPI app under app/ exposing validation endpoints. Each email goes through format, MX, then SMTP recipient verification.

Architecture Diagram

graph LR
    ClientRequest["Client / Postman / CSV"]
    FastApiApp["FastAPI app.main"]
    DnsMxLookup["DNS MX lookup"]
    SmtpRecipientCheck["SMTP RCPT TO check"]

    ClientRequest -->|"POST validate email or CSV"| FastApiApp
    FastApiApp -->|"checks mail servers exist"| DnsMxLookup
    FastApiApp -->|"verifies recipient mailbox"| SmtpRecipientCheck

How to read this diagram

Arrows mean flow / dependency / "talks to", not button clicks. Each arrow label says what happens on that step.

Validation flow

1. Email format check
2. DNS MX record lookup
3. SMTP recipient verification (RCPT TO)

Technology Stack

Layer	Technology
API	FastAPI + Uvicorn
Packaging	Docker
QA	Postman collection

Next Steps

• API Reference
• Getting Started
• Overview