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Free tool

Cold email domain checker

By Wasey Mohammed, FounderUpdated October 26, 2026No sign-up. Runs in your browser.

Check every domain your firm sends business development email from before Gmail, Yahoo or Outlook decide for you. It reads the live DNS records, counts SPF lookups the way receivers do, finds DKIM keys and their strength, checks DMARC, MX, domain age and the website, and gives you a plain verdict with the fix for each problem.

Your main domain and every sending domain. An email address or a website link works too.
We try the common ones for Google, Microsoft, SendGrid, Mailchimp and others. Add yours if it’s custom.
Try:
Add the domains you send from and press Check domains. The lookups go from your browser to Google’s public DNS and the rdap.org registration directory. Nothing is stored.
When you want more than a tool

A clean domain is the start. The job orders come from what you send.

Use the checker as often as you like. When you want the domains, the inboxes and the outreach run for you, that’s Wavaron.

Free, right hereCold email domain checker
  • Up to 5 domains at a time
  • SPF, DKIM, DMARC, MX, age and website
  • Copy the report for your IT provider
You’re using it now.
Free, done by our teamMarket scan
  • We scan the employers in your niche and city
  • 3 companies worth calling this week, who signs, and why now
  • On a 30-minute strategy call. You keep the list either way
Get your free market scan
WavaronThe full system, run for you
  • Sending domains and inboxes set up and warmed in your firm’s name
  • Your whole market watched every week, the signer found for every opportunity
  • Your ATS candidates matched to each role
  • Approved outreach, replies routed to your recruiters
  • First play live in 30 days, or your first month is free
Book a strategy call

What it checks, and why

MXWhether the domain can receive mail, and who hosts it. Replies have to reach a real inbox, and Microsoft expects the From or Reply-To address to accept mail.
SPFOne record listing who may send as you. We count every DNS lookup it triggers, following each include, because the standard caps it at 10 and allows 2 lookups that return nothing. Past either limit, SPF fails everywhere. More than one SPF record fails too.
DMARCTells receivers what to do when SPF or DKIM fail, and where to send reports. Gmail, Yahoo and Outlook require it for domains sending 5,000 or more messages a day, and p=none meets that rule.
DKIMA signature on every message. We look for keys at the selectors the major providers use, and read the key length. Google recommends 2048-bit keys where your provider supports them.
Domain ageFrom the public registration record. A brand-new domain has no sending history, so it needs a gradual warm-up before any cold volume.
WebsiteWhether the domain points anywhere. People check who emailed them; a sending domain should lead to your real site.

How staffing firms should set up sending domains

  • Never send cold business development email from your main domain. It carries your client and candidate email, and a reputation problem there hits everything. Tick “main company domains” above and the checker will remind you.
  • Use separate sending domains that are clearly yours, such as variations of your firm’s name, and point each one at your website.
  • Authenticate every one: SPF, DKIM with a 2048-bit key, and DMARC with reporting turned on.
  • Warm up gradually over several weeks before real volume, and keep spam complaints under 0.1% in Google Postmaster Tools.
  • Follow CAN-SPAM: a real postal address and an opt-out you honor within 10 business days, even for B2B email.

The full rules, with sources, are in our cold email deliverability guide.

Fixing the common problems

  • Too many SPF lookups: remove tools you no longer send from, and ask providers for their IP ranges if you need to flatten the record. Never publish a second SPF record to add a service; merge it into the first.
  • No DMARC: add a TXT record at _dmarc.yourdomain with v=DMARC1; p=none; rua=mailto: and an address you read. Move to quarantine, then reject, once every legitimate sender passes.
  • No DKIM found: turn on signing in your mail provider (Google Workspace and Microsoft 365 both have it in the admin console) and publish the key it gives you. If you already sign with a custom selector, enter it above.
  • 1024-bit DKIM key: generate a new 2048-bit key, publish it, then switch signing over.

What it can’t see

  • Your sending reputation and inbox placement. Use Google Postmaster Tools and Microsoft’s sender support for that.
  • Blocklists. Major lists don’t answer lookups from public DNS resolvers, so we don’t pretend to check them.
  • Custom DKIM selectors we don’t know about. Enter yours to check it.
  • Content, volume and list quality, which matter as much as setup.

Questions owners ask

Why does my email go to spam even though SPF is set up?

SPF alone isn’t enough. Gmail, Yahoo and Outlook also look for DKIM and DMARC on bulk senders, and SPF itself fails if the record needs more than 10 DNS lookups or there are two SPF records. Reputation, complaints and content matter too.

What is the SPF 10 lookup limit?

The SPF standard allows at most 10 DNS-querying terms (include, a, mx, ptr, exists and redirect), counted across every nested include. Beyond that the result is a permanent error, and receivers treat your SPF as failed.

Is DMARC p=none enough?

It meets the Gmail, Yahoo and Outlook requirements for bulk senders. It doesn’t protect your domain from spoofing, so plan to move to quarantine and reject once your reports show every legitimate sender passing.

Should we send cold email from our main domain?

No. Use separate, authenticated and warmed sending domains so any reputation damage stays away from the email your clients and candidates rely on.

What do you see or store?

Nothing. The lookups go from your browser to Google’s public DNS (or Cloudflare’s as a fallback) and to rdap.org for the registration date. Those services see the domain names you check; Wavaron doesn’t.

Sources