I just launched Email Validator API on RapidAPI — a professional email
verification service built with Python and FastAPI.
Most email validators only check syntax. Mine runs 4 layers of verification
and returns a confidence score for every email.
The 4 Layers
Layer 1 — Syntax Check
Validates format against RFC 5322 standards. Also detects common typos
and suggests corrections — for example user@gmial.com → user@gmail.com.
Layer 2 — DNS / MX Lookup
Confirms the domain exists and is configured to receive emails using
dnspython. Catches domains that look valid but can't receive mail.
Layer 3 — Disposable Domain Detection
Flags throwaway addresses from 3,000+ known providers like Mailinator,
Guerrilla Mail, YOPmail and TempMail. Essential for preventing fake signups.
Layer 4 — SMTP Verification
Performs a real SMTP handshake to confirm the mailbox exists — without
sending a single email. Available on Pro plans.
The Response
Every request returns a detailed JSON breakdown:
{
"email": "user@gmail.com",
"valid": true,
"score": 95,
"syntax_valid": true,
"mx_found": true,
"disposable": false,
"smtp_valid": true,
"suggestion": null,
"error": null
}
Score Interpretation
| Score | Meaning |
|---|---|
| 0–29 | Invalid syntax |
| 30–54 | Domain issues |
| 55–74 | Likely valid |
| 75–94 | Valid + not disposable |
| 95–100 | Fully verified via SMTP |
Tech Stack
- FastAPI — async endpoints, automatic Swagger docs
- dnspython — async DNS/MX lookups
- slowapi — rate limiting per plan tier
- Render — deployment
- RapidAPI — marketplace and monetization
Plans
| Plan | Requests/month | Layers | Price |
|---|---|---|---|
| BASIC | 100 | 1–2 | Free |
| PRO | 5,000 | 1–3 | $9/mo |
| MEGA | 20,000 | 1–4 | $19/mo |
| ULTRA | 50,000 | 1–4 + bulk | $29/mo |
Try it
🔗 https://rapidapi.com/PabsCueto/api/email-validator-api32
Free plan available — no credit card required.
Happy to answer questions about the implementation!