Email Deliverability Checklist

Only about 85% of legitimate marketing emails actually reach the inbox—the rest land in spam or get blocked entirely. That means if you're sending to 10,000 subscribers, roughly 1,500 might never see your email. This interactive checklist covers the 26 practices that separate senders with 98%+ inbox placement from those struggling to break 80%. Work through it systematically—each item you check off directly improves your deliverability.

The Authentication Trio: SPF, DKIM, and DMARC

Email authentication is non-negotiable in 2024+. You need all three: SPF tells receiving servers which IPs can send email for your domain. DKIM cryptographically signs each email so receivers can verify it hasn't been tampered with. DMARC ties them together with a policy that tells receivers what to do when authentication fails. Missing even one of these three means Gmail, Yahoo, and Outlook will treat your emails with suspicion. Use our generators (SPF, DKIM, DMARC) to set them up, then verify with the checkers.

List Hygiene: The Foundation of Reputation

Your sender reputation is only as good as your list. Validate every email at signup using real-time verification. Implement double opt-in for web forms—it reduces list size by 20-30% but virtually eliminates spam traps and fake signups. Remove hard bounces immediately after every campaign. Suppress addresses that soft-bounce 3+ times. Run a re-engagement campaign for subscribers who haven't opened in 90 days, then remove the non-responders. Never, ever buy or rent email lists.

Content Quality and Sending Patterns

Even with perfect authentication and a clean list, your content matters. Avoid common spam trigger words (use our spam word checker). Maintain a healthy text-to-image ratio—all-image emails get filtered aggressively. Keep your HTML clean and under 100KB. Send consistently—sudden spikes in volume trigger ISP scrutiny. If you're ramping up volume, use a warmup schedule to gradually increase sends over 4-8 weeks.

Ongoing Monitoring and Quick Response

Deliverability isn't a one-time setup—it's ongoing maintenance. Check your domain against blacklists weekly. Monitor your bounce rate after every campaign. Track your unsubscribe rate—Gmail's threshold is 0.3%, and exceeding it triggers filtering. Watch for sudden drops in open rates, which often signal deliverability issues before they become critical. Run this full checklist quarterly to catch drift.