Email Auth API

Getting started

Subscribe, copy your secret key, and run your first Email Auth lookup.

The Syndaq Email Auth API inspects a domain's outbound email authentication setup. Each lookup returns SPF, DKIM, and DMARC presence with the raw records when found, plus a composite score from 0–100.

What you need

  1. An Email Auth plan from the Syndaq API catalog.
  2. A secret key (ea_sec_) from the Syndaq client area after your order is provisioned.

Email Auth lookups are server-side only. Send your secret key from your backend or trusted worker. Do not embed it in client-side code, mobile apps, or public repositories.

Base URL

All Email Auth endpoints are served from:

https://api.syndaq.com/v1/emailauth/

Quick start

Replace ea_sec_YOUR_SECRET_KEY with the secret shown in Services for your Email Auth subscription.

curl -sS "https://api.syndaq.com/v1/emailauth/lookup/example.com" \
  -H "Authorization: Bearer ea_sec_YOUR_SECRET_KEY"

You can also pass the domain as a query parameter:

curl -sS "https://api.syndaq.com/v1/emailauth/lookup?domain=example.com" \
  -H "Authorization: Bearer ea_sec_YOUR_SECRET_KEY"

A successful response includes a numeric score plus structured spf, dkim, and dmarc objects.

How lookups work

StepWhat happens
1Authenticate with your secret key.
2Send a domain lookup request to the API.
3Receive JSON with the result fields (including a cached flag when Syndaq already holds a recent result).

Invalid domains return a clear error.

Manage your subscription

Sign in to the Syndaq client area and open Services. Select your Email Auth service to:

  • View usage and remaining monthly quota
  • Copy or rotate your secret key
  • Configure optional IP allowlists for API access

Next steps