Email Deliverability Audit Checklist
Deliverability dropping and not sure why? A structured audit finds the leak. Work through this checklist to diagnose and fix inbox placement problems.
TL;DR
Audit five areas: authentication, reputation, list health, content and infrastructure. Fix issues in order of impact. Most deliverability problems trace back to one of these — this checklist finds it.
1. Authentication
- SPF valid and under 10 lookups?
- DKIM signing and aligned?
- DMARC published and enforcing?
- rDNS/PTR matching on every IP?
2. Reputation
- Check IP/domain reputation in Postmaster Tools & SNDS.
- On any blacklists?
- Sender Score 90+?
3. List health
- Bounce rate under 2%?
- Complaint rate under 0.1%?
- Practising list hygiene and opt-in?
4. Content
- Healthy text-to-image ratio and plain-text part?
- Subject lines clean of spam triggers?
- Clear unsubscribe link?
5. Infrastructure
- Port 25 open; proper server?
- Dedicated IPs warmed?
- Throttling tuned per ISP?
Prioritise by impact
Fix authentication and blacklists first (biggest, fastest wins), then reputation and list health, then content and tuning.
AutoPMTA's DNS Health and monitoring run much of this audit automatically. View plans.
Key takeaways
- Audit authentication, reputation, list, content, infrastructure.
- Authentication and blacklist issues are the fastest wins.
- Keep bounces <2% and complaints <0.1%.
- Fix in order of impact, then monitor continuously.
Frequently asked questions
How do I audit my email deliverability?+
Check five areas in order: authentication (SPF/DKIM/DMARC/rDNS), reputation (Postmaster Tools, blacklists, Sender Score), list health (bounce and complaint rates), content (text ratio, subject lines, unsubscribe), and infrastructure (port 25, IPs, throttling).
What hurts email deliverability the most?+
Missing or broken authentication and blacklist listings have the biggest, fastest impact. After those, poor reputation from high complaints or bounces is the most common cause.
How often should I run a deliverability audit?+
Run a full audit quarterly or whenever inbox placement drops, and monitor key metrics (reputation, bounces, complaints, blacklists) continuously between audits.