n8n Webhook: Email Deliverability Check (Google DNS + Cloudflare Fallback)

Instant email deliverability check via webhook—using Google DNS with a Cloudflare fallback

This n8n workflow gives you a simple HTTP webhook that verifies an email address’s domain deliverability by checking for DNS MX records. It uses Google DNS-over-HTTPS first and automatically falls back to Cloudflare DNS-over-HTTPS if the Google lookup errors or times out, returning a clear JSON verdict.

What this workflow does

• Receives an HTTP request on an n8n Webhook endpoint, with the email provided either as a ?email= query parameter (GET) or in the JSON body as { "email": "..." }.
• Validates and normalizes input: extracts the email and domain, and rejects malformed inputs with a 400 response.
• Checks MX records with Google: queries dns.google (DNS-over-HTTPS) to resolve MX records for the domain.
• Returns a 200 JSON result:
  • Valid when MX records are present
  • Invalid when no MX records are returned
• Falls back to Cloudflare if needed: if the Google DNS lookup errors or times out, it repeats the MX lookup using Cloudflare.
• Returns the final verdict from whichever resolver succeeded (including which resolver produced the result).

Use cases

• Verify new user emails during signup to reduce bounce rates.
• Pre-flight checks for SaaS onboarding emails—catch domains with missing MX records.
• Automate deliverability gating for bulk outreach or transactional notifications.
• Build an API-style email validation step inside your n8n automation engineers’ workflows.

Technical details

• Workflow type: n8n automation workflow
• Nodes used: if, set, webhook, sticky note, http request, respond to webhook
• Resolvers: Google DNS-over-HTTPS (dns.google) with Cloudflare DNS-over-HTTPS fallback (cloudflare-dns.com)

Setup tip: Import the workflow and use the production webhook URL. Ensure outbound HTTPS access is allowed to dns.google and cloudflare-dns.com.