Email Deliverability Checklist

Ensure your emails land in the inbox

Getting emails to the inbox is not just about content. Your infrastructure, authentication, and reputation all play a role. Use this checklist to audit your setup before every major campaign or when troubleshooting delivery issues.

1 DNS Authentication

SPF record published and valid (no syntax errors, under 10 lookups)
DKIM record published and the private key is signing outbound mail
DMARC record published with a policy of at least p=none (ideally p=quarantine or p=reject)
Reverse DNS (PTR) exists for your sending IP and matches your sending domain
MX record resolves correctly and accepts mail at your domain

2 Reputation and Blacklists

IP and domain checked against major RBLs (Spamhaus, Barracuda, SpamCop, SURBL)
Sender Score or similar reputation service shows a healthy score (above 80)
No recent spam complaints or elevated bounce rates
Warming up new IPs gradually before sending high volume

3 Content and Engagement

Subject lines avoid spam trigger words ("FREE!!!", "Act now", excessive caps)
Text-to-image ratio is balanced (not one giant image)
HTML is clean and mobile-responsive with working unsubscribe link
List is double-opt-in and regularly cleaned of inactive subscribers

4 Testing Before Sending

SpamAssassin or Mail-Tester score is above 8/10
Seed tests sent to Gmail, Outlook, Yahoo, and Apple Mail inboxes
All links are functional and point to HTTPS destinations
From name and reply-to address are recognizable and trustworthy

Quick audit with Postalfix

Run these tools to validate the infrastructure items on this checklist:

DNS Lookup Blacklist Checker Reverse DNS DKIM Checker

Related Tools

Check MX, SPF, DMARC, TXT, A and NS records

Blacklist Checker

Verify if your IP or domain is on any spam blacklists

Look up DKIM records by domain and selector

Reverse DNS Lookup

Find the hostname for any IP address or domain

SPF Record Generator

Build a valid SPF record to prevent email spoofing