For the complete site index, see llms.txt. Docs index: llms-docs.txt. Marketing corpus: llms-full.txt. Docs corpus: llms-full-docs.txt. Prefer markdown URLs where available (append .md).. Product skill: skill.md. Pricing: pricing.md. Docs MCP: /docs/mcp. Site MCP: /mcp.

Domain Authentication

Authenticate Your Domain in 2 Minutes

Add sending domains and verify SPF, DKIM, and DMARC with automated DNS validation, 2048-bit keys, and real-time deliverability checks.

Start for free

Free tier: Unlimited sending domains. Zero DNS lock-in.

DNS as Code

Provision & verify domains via API.

Automate domain provisioning in CI/CD pipelines, multi-tenant SaaS apps, and agentic workflows with our TypeScript SDK and CLI.

reloop domains add <domain>reloop domains verify <id>
domain.ts
1import Reloop from 'reloop-email';
2

3const reloop = new Reloop(process.env.RELOOP_API_KEY);
4

5// Register a new custom domain
6const domain = await reloop.domains.create({
7  name: 'acme.com',
8  region: 'us-east-1',
9});
10

11// Check automated DNS verification status
12const status = await reloop.domains.verify(domain.id);
13console.log(status.dkim.status); // "verified"
DNS Verification
1/4

Automated record diagnostics.

Zero DNS guesswork. Reloop validates name servers, checks propagation across global resolvers, and flags misconfigurations instantly.

DKIMrl._domainkey.acme.com
Verified

2048-bit RSA key cryptographic identity signature

SPFacme.com
Aligned

Authorizes Reloop edge MTAs to deliver from your domain

DMARC_dmarc.acme.com
Enforced

Strict policy protecting against sender spoofing & phishing

RETURN-PATHmail.acme.com
Custom Mail-From

Custom envelope domain to eliminate 'via reloop.sh' warnings

AI Native

MCP Domain Tools

mcp.sh
1# Connect Claude to Reloop
2claude mcp add reloop \
3  -e RELOOP_API_KEY=rl_xxx \
4  -- npx -y reloop-mcp

Give Claude Desktop, Cursor, or your agentic backend direct tools to add sending domains, inspect DKIM records, and test DNS propagation.

Explore MCP Server

Developer CLI

verify.sh
1# Verify DNS records
2reloop domains verify \
3  --name acme.com \
4  --check-dns \
5  --json

Deterministic CLI for humans and agents. Verify SPF/DKIM records, monitor propagation, and stream DNS diagnostics in machine-readable JSON.

CLI Reference

Agent Skills

skills.sh
1# Install CLI agent skill
2npx skills add \
3  reloop/reloop-skills \
4  --global

Equip Cursor, Claude Code, and autonomous coding agents with expert DNS troubleshooting instructions and automated Cloudflare/Route53 scripts.

Install Agent Skills
DNS Integrations

Works with any DNS host or registrar.

Whether you manage DNS on Cloudflare, AWS Route 53, Google Cloud, or self-hosted BIND servers, Reloop validates TXT and CNAME records effortlessly.

View DNS setup guides
Cloudflare
AWS Route 53
Google Cloud
DigitalOcean
Hetzner
Supabase
GitHub
Coolify
Railway
Render
Vultr
Kubernetes
Docker
Domain Capabilities

Built for flawless email authentication.

2048-Bit DKIM Keys

Cryptographically sign every email with auto-generated RSA-2048 keys for maximum recipient trust.

SPF Alignment

Authorize Reloop's global MTAs with strict SPF inclusion, keeping DNS lookup limits well below 10.

DMARC Enforcement

Safeguard your domain against spoofing with guided transitions from p=none to p=reject.

Custom Return-Path

White-label your envelope MAIL FROM address to eliminate 'sent via' warnings in email clients.

Subdomain Isolation

Isolate transactional, marketing, and notification email reputations across distinct subdomains.

Instant Verification

Automated resolver polling checks DNS propagation across global regions within seconds.

BIMI & Brand Avatars

Configure Brand Indicators for Message Identification (BIMI) to display your SVG logo in inboxes.

Zero-Downtime Rotation

Rotate cryptographic DKIM keys seamlessly without dropping in-flight deliveries.

Multi-Domain Tenancy

Provision and manage custom sending domains programmatically for all of your SaaS customers.

Blocklist Telemetry

Continuous automated monitoring across Spamhaus, URIBL, and SURBL to protect sender reputation.

Start now
$0 / mo.

No credit card required. Unlimited domains with automated DNS verification.

Get startedDomain docs
Reloop