Cold Email Deliverability Checker

How this checker works

The 15 questions cover the five categories that determine whether your cold email reaches the inbox or gets filtered as spam. Each answer is weighted based on how much impact it has on real deliverability outcomes (based on data from Google's Postmaster Tools, Litmus, and years of operator experience).

The five categories audited

• DNS setup (SPF, DKIM, DMARC): the three DNS records that tell Gmail and Outlook your sending domain is legitimate. Missing any one of them and your deliverability is compromised before you write your first email.
• Sending domain: whether you use a dedicated cold email domain (recommended) or your main company domain (risky). Sending from your main domain means one bad campaign can torch your transactional and marketing email too.
• Warmup: whether you ran a proper 14 to 21 day warmup on new inboxes and keep low-level warmup running in the background during active campaigns. Skipping this is the #1 reason new senders land in spam.
• Sending caps and cadence: whether your daily send volume, random delays between sends, and stop-on-reply settings match what a real human sender looks like to Gmail's algorithms.
• List quality and verification: whether every address gets verified before it enters your sequence, and how you handle catch-all domains. A single bounce spike from an unverified list can drop your sending reputation for weeks.

What the score means

• 80 to 100 (green): your setup is solid. Focus on copy, targeting, and follow-up cadence. Deliverability is not your bottleneck.
• 50 to 79 (amber): your setup has gaps that limit inbox placement. Fix the top-priority items highlighted in your report before scaling send volume.
• Under 50 (red): pause your sending. Your setup will damage sender reputation if you push volume before fixing the foundational issues.

What this tool is not

The DNS check at the top reads what a domain publishes. That is a fact, and it settles questions like which provider a domain sends through or whether DMARC is actually enforcing. It is not proof of inbox placement. The 15 questions below are an audit of your setup, and the answers are yours, so the score is only as honest as they are.

Neither is a real-time placement test. For that you need probe emails sent through your own infrastructure and reported back per mailbox provider, which is what GlockApps and MXToolbox do. Blocklist status is a third thing again, and it cannot be read from a web page: Spamhaus, Barracuda and the others refuse queries arriving through public resolvers, so a browser has no way to ask. Query them from your own resolver, or use a service with a licensed feed.

If you only need one record read, there is a focused page for each: the SPF record checker, the DKIM record checker and the DMARC record checker. They run the same engine and explain that record in depth.

We ran this same check across 156 B2B lead generation agencies in August 2026. Eighty-seven of them carry a real defect on their own domain, and only 30 enforce DMARC at p=reject. The full counts and method are in the agency DNS audit.

Check a domain →