Free tool

Receiver requirements checker for cold email

Check the public authentication records and optional message-header evidence that receiver requirements depend on before a campaign launches.

This checks receiver-facing authentication and unsubscribe evidence for one domain. For a real launch verdict, run every domain, inbox, and tracking domain through the full QA pass.

Runs live in your browser via public DNS and local header parsing. Nothing is stored.

DNS can pass while the message still needs review

A published SPF, DKIM, or DMARC record does not prove that the sender used it on the message that will launch. Receiver requirements also depend on alignment, unsubscribe handling, TLS, message format, volume, and complaint signals.

Run the domain check first. Then paste headers from a real test message when you have them. Headers stay in your browser and are not sent to a backend.

How to read the result

A pass means the observable evidence in the check is present. A warning means a header, SMTP, complaint, or message-body signal still needs review. A fail means the public records or pasted headers contain a confirmed blocker.

This is not an inbox-placement score. Use the PTR and rDNS checker for a custom SMTP egress path, then run the full cold email pre-launch checklist before client signoff.

Provider requirements are not one universal rule

Gmail, Yahoo, and Microsoft publish overlapping authentication expectations with different thresholds and enforcement details. The result groups their shared observable checks, then identifies what remains outside a browser lookup.

What this check does not catch

A passing receiver-facing authentication and unsubscribe evidence lookup is useful, but it is not launch signoff. Cold email campaigns still fail when adjacent records, tracking domains, or inbox-level settings are broken.

live SMTP TLS

PTR/rDNS for the sending IP

complaint rate

message body formatting

inbox placement

client-ready signoff

Setup guides for this check

Read the setup notes behind this result, then verify the neighboring records before launch.

Google and Yahoo bulk sender requirements

SPF, DKIM, DMARC, one-click unsubscribe, and the spam-rate thresholds bulk senders must meet.

SPF for cold email

The exactly-one-record rule, the 10 DNS lookup limit, and the SPF mistakes that block a launch.

DKIM for cold email

Selectors, public keys in DNS, and DKIM setup for Google Workspace and Microsoft 365.

DMARC for cold email

Policies, alignment, rua reports, and the Gmail and Yahoo requirement that made DMARC mandatory.

Need to check a full outbound workspace?

OutboundQA checks every domain, inbox, and tracking domain in the workspace, then gives you a shareable report with a Ready, Needs Fix, or Do Not Launch verdict.

Run a free workspace check View a sample report

Cold email launch checks to run next

Use this result as one checkpoint in the launch flow. Then verify the neighboring records and run the combined domain check before the outbound launch goes live.

SPF Checker

Look up a domain's SPF record and count its DNS lookups against the limit of 10.

DMARC Checker

Look up a domain's DMARC record and read its policy in plain English.

DKIM Checker

Look up a domain's DKIM selector and confirm the public key exists.

Auth Checker

Run SPF, DKIM, and DMARC together for a sending domain before launch.

MX Checker

Look up a domain's MX records and detect the mail provider.

Blacklist Checker

Check a domain and sampled mail server IPs against domain and email blocklists.

Reputation Checker

Check observable cold email reputation risks across age, blacklist, authentication, MX, and HTTPS signals.

Deliverability Checker

Check observable cold email infrastructure readiness across MX, SPF, DKIM, DMARC, blacklist, age, tracking-domain, and SMTP egress identity signals.

Recipient Preflight

Paste emails or domains and classify MX provider, free inboxes, security gateways, SPF, DMARC, and receive-mail readiness.

Tracking Checker

Check a branded cold email tracking domain for CNAME setup, DNS resolution, HTTPS, and redirect handoff.

MTA-STS Checker

Check MTA-STS and TLS-RPT records for inbound mail security posture before a cold email launch.

PTR/rDNS Checker

Check a custom SMTP egress IP for PTR, reverse DNS, and forward-confirmed rDNS before launch.

Launch Checklist

Generate a pre-launch QA checklist for domains, inboxes, authentication, tracking domains, blacklist checks, and signoff.

Domain Checker

Run MX, SPF, and DMARC in one pass for a quick readiness verdict on a sending domain.

Sample Launch QA Report

See the report founders, teams, and agencies can share after the full QA pass.

Email Deliverability Tool

See how one-off checks turn into pre-launch QA for full cold email workspaces.

Questions

It checks public SPF, DKIM, DMARC, and MX evidence for one domain. If you paste headers from a real message, it also reads authentication results, DMARC alignment evidence, and one-click unsubscribe headers.

DNS shows that records are published. Headers show what a real sender path reported for SPF, DKIM, DMARC, and unsubscribe handling. Paste headers when you have already sent a test message from the campaign setup.

No. It checks observable setup evidence. Receiver decisions also depend on volume, complaints, message content, list quality, sending history, and signals that a browser tool cannot inspect.

Marketing and promotional messages are checked for RFC 8058 one-click unsubscribe headers. Transactional messages show that row as not scored, but the other authentication checks still apply.

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