Free tool

Free DKIM record checker

Look up a DKIM selector for a sending domain and see whether the public key exists before a cold email launch.

This checks DKIM selector 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. Nothing is stored.

How to read the result

A DKIM record usually lives at selector._domainkey.yourdomain.com. A healthy selector returns one TXT record with a public key in p=. If the selector is unknown, test the selector from your actual sending platform before treating the domain as ready.

DKIM is one of the authentication checks OutboundQA runs across every workspace domain and inbox. A single passing selector is useful, but a launch verdict needs the selector matched to the tool that will send the campaign.

What this check does not catch

A passing DKIM selector 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.

SPF lookup limits

DMARC alignment

MX readiness

tracking-domain SSL

blacklist status

inbox-level sending setup

Setup guides for this check

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

Google and Yahoo bulk sender requirements

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

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.

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.

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.

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

A selector is the DNS label your mail provider uses to find the right DKIM key. The lookup happens at selector._domainkey.yourdomain. Common selectors include google, selector1, selector2, s1, and s2, but every provider can choose its own value.

DKIM signs outbound mail so receivers can verify the message was authorized by the domain. Without DKIM, DMARC alignment is weaker and Google or Microsoft may treat the campaign as higher risk.

Check your sending platform's domain authentication screen. Google Workspace commonly uses google, Microsoft often uses selector1 and selector2, and many outbound tools use s1 or s2. Unknown selector is different from failed DKIM, so test the selector your platform actually sends with.