Email Deliverability Checker

• Reference signals: Hello Inbox positions itself as an AI deliverability expert; GlockApps offers spam checking, inbox placement, blacklist checks, and SPF/DKIM/DMARC validation; MXFend, EmailToolBox, MailRisk, and DeliverabilityChecker cover DNS and security checks.
• Competitors mainly fall into three groups:
• DNS/authentication checkers: SPF, DKIM, DMARC, MX, BIMI, MTA-STS, TLS-RPT.
• Inbox placement / spam tests: useful but require seed mailboxes or a receiving email system, so they are not right for the first version.
• Deliverability consulting / warmup suites: service- or subscription-heavy, good for later monetization.
• The gap: many tools are too technical and return raw DNS results, while others quickly push warmup or consulting. A lightweight tool for creators, indie SaaS founders, and cold email users can win by turning checks into clear next steps.

MVP Checklist

1. 1.Build page structure and global SEO metadata.
2. 2.Implement Checker form, validation, loading, and error states.
3. 3.Implement DNS lookup in `app/api/check/route.ts`.
4. 4.Implement SPF, DMARC, MX, and DKIM parsing and basic checks.
5. 5.Implement BIMI, MTA-STS, and TLS-RPT presence checks.
6. 6.Implement scoring and critical/warning/pass classification.
7. 7.Implement repair recommendations and Markdown report generation.
8. 8.Complete About, FAQ, schema, and Open Graph metadata.
9. 9.Manually test real domains: gmail.com, github.com, and the user's own or test domain.
10. 10.Fix mobile layout and error states.

Don't Build

• ✕Do not expand features without confirmation.
• ✕Do not add a complex backend unless core functionality requires it.
• ✕Do not start with login, payment, membership, or admin unless core functionality requires it.
• ✕Do not sacrifice launch speed for unnecessary completeness.
• ✕**Do not cut the core feature just to make the project lighter.**
• ✕Do not market DNS readiness checks as real inbox placement tests.
• ✕Do not send email or modify DNS automatically.