Deliverability Toolkit

The classic — SPF, DKIM, DMARC, MX, blacklist checks all in one place.

Propagation checker — see what every public resolver worldwide returns.

Deliverability toolkit with SPF flattening, DMARC parsing, aggregate reports.

Visualize your full SPF record as a tree, count DNS lookups.

Validate DMARC records, see policy, generate records.

Comprehensive deliverability scoring for a single sent email. Complementary to InboxGrade.

The one blacklist that matters. Check IP and domain reputation.

Barracuda's blocklist — delisting takes 24-48h once requested.

150+ blacklists in one query. Overkill but handy for forensics.

Score your receiving MTA's TLS posture, cipher negotiation, cert chain.

Full-stack domain security audit — MTA-STS, DANE, TLS-RPT, DNSSEC.

Validate your MTA-STS policy file end-to-end.

See how Gmail scores your domain reputation. Essential for high-volume senders.

Microsoft's sender dashboard — IP reputation, complaint data, delivery metrics.

Yahoo/AOL deliverability dashboard + feedback loop signup.

The actual SPF spec — including the famous 10-DNS-lookup limit.

DMARC spec. Dense but definitive.

The messaging industry's working-group recommendations. Deep but authoritative.