Recursive SPF with the 10-lookup limit, DKIM keys and DMARC policy
Email Spam & Deliverability Checker
A professional, multi-layer audit of subject, preheader, content, HTML, headers and domain authentication—with separate scores, clear evidence and actionable fixes. No database required.
Workspace
HTML is detected automatically. Code is never executed and content is not uploaded.
Raw headers (optional, improves confidence)
Findings by priority
Live domain authentication check
Optional: only the domain name is sent to your selected public DNS resolver; message content is never sent or stored.
How is the result calculated?
Four independent scores start at 100: subject 25%, content hygiene 35%, message structure 25%, and technical signals 15%. Without headers, weight is redistributed across the three available scores and confidence is shown as 72%; with headers it becomes 88%. Every deduction appears as a finding with its severity and value—there are no hidden factors.
- Subject: 30–60 character target, caps, exclamation marks, emoji, deceptive reply prefixes and the weighted spam lexicon.
- Content: spam phrases, link density, shorteners, HTTP and IP links, unsafe or hidden HTML, alt text, link mismatch, image heaviness, and Gmail's 102,400-byte clipping threshold.
- Structure: duplicate subject/preheader, unresolved merge tags, and unsubscribe/address signals for marketing messages.
- Technical: SPF/DKIM/DMARC results as written by the receiving server, domain alignment, Message-ID and Date, plus an independent DNS check for SPF, DMARC, MX and an optional DKIM selector.
Accuracy limits: This is a preflight audit, not Gmail's or Outlook's filter, and it cannot guarantee inbox placement. IP/domain reputation, list engagement, complaints, blocklists, recipient context and provider policy require real sending and provider data. Headers can be forged unless supplied by a trusted receiving server, and DNS presence does not prove a valid signature. Message content is never sent or stored; only the optional DNS check makes a network request.
FAQ
Does it work without a database or backend?
Yes. Analysis, import and report generation run in the browser. The optional DNS check queries Google Public DNS or Cloudflare directly.
Does a high score guarantee inbox delivery?
No. It means the message passes the measurable rules here. Send to real seed accounts and monitor provider data.
