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Email Deliverability Audit: The Complete Checklist for 2026

Kawaa Team
January 22, 2026
18 min read
Email Deliverability Audit: The Complete Checklist for 2026

Your emails are getting sent, but are they actually landing in inboxes? For many email marketers, the answer is uncertain at best. Poor deliverability silently destroys campaign performance—you won't see “went to spam” in your analytics. This comprehensive audit checklist will help you identify and fix every factor affecting your email deliverability.

What This Audit Covers

  • Email authentication (SPF, DKIM, DMARC)
  • List hygiene and data quality
  • Sender reputation analysis
  • Infrastructure configuration
  • Content optimization
  • Monitoring and alerting setup

Why Audit Your Email Deliverability?

Email deliverability isn't a set-it-and-forget-it metric. It degrades over time as:

  • Email addresses in your list become invalid (22% annual decay rate)
  • Spam filters evolve and become more sophisticated
  • Your sending patterns change with business growth
  • Domain and IP reputation fluctuates based on engagement
  • Competitors and bad actors may impact shared IP reputation

The cost of poor deliverability: If your deliverability drops from 95% to 85%, you're losing 10% of every campaign. For a 100,000-subscriber list sending weekly, that's 520,000 missed impressions per year—a significant revenue impact.

Section 1: Email Authentication

Authentication tells inbox providers that emails from your domain are legitimate. Without proper authentication, your emails are far more likely to be marked as spam or rejected entirely.

SPF (Sender Policy Framework)

SPF specifies which mail servers are authorized to send email on behalf of your domain.

SPF Audit Checklist

# Example SPF record

v=spf1 include:_spf.google.com include:sendgrid.net include:amazonses.com -all

DKIM (DomainKeys Identified Mail)

DKIM adds a digital signature to your emails, proving they haven't been modified in transit.

DKIM Audit Checklist

DMARC (Domain-based Message Authentication)

DMARC tells receivers what to do when SPF or DKIM fails, and provides reporting on authentication results.

DMARC Audit Checklist

# Recommended DMARC record

v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com; pct=100; adkim=s; aspf=s

DMARC PolicyWhat HappensRecommendation
p=noneNo action, just reportingStart here, then upgrade
p=quarantineFailures go to spamGood protection
p=rejectFailures are blockedBest protection

Section 2: List Hygiene

List quality directly impacts deliverability. Sending to invalid addresses, spam traps, or unengaged subscribers tells inbox providers you don't maintain good sending practices.

List Hygiene Audit Checklist

< 2%
Target Bounce Rate

Above 5% triggers ESP warnings; above 10% risks suspension

22%
Annual Email Decay

Expect ~22% of your list to become invalid each year

Section 3: Sender Reputation

Your sender reputation is a score that inbox providers use to decide whether to deliver, spam, or block your emails.

Reputation Audit Checklist

ToolWhat It ShowsURL
Google Postmaster ToolsDomain reputation, spam rate, authenticationpostmaster.google.com
Microsoft SNDSIP reputation, spam complaints, trap hitssendersupport.olc.protection.outlook.com
MXToolboxBlacklist check (50+ lists)mxtoolbox.com/blacklists.aspx
Sender ScoreIP reputation score (0-100)senderscore.org

Section 4: Infrastructure

Your technical email infrastructure affects deliverability in ways that aren't immediately obvious.

Infrastructure Audit Checklist

IP Warmup is Critical: New IPs have no reputation. Sending at full volume immediately will trigger spam filters. Gradually increase volume over 4-8 weeks, starting with your most engaged subscribers.

Section 5: Content Optimization

While content-based filtering is less dominant than it once was, certain patterns still trigger spam filters.

Content Audit Checklist

AVOID

ALL CAPS in subject lines or body text

AVOID

Multiple exclamation points or special characters!!!

AVOID

Image-only emails with no text

AVOID

Misleading subject lines that don't match content

Section 6: Ongoing Monitoring

Deliverability isn't a one-time fix. Set up monitoring to catch issues before they become crises.

Monitoring Audit Checklist

Your 30-Day Action Plan

Don't try to fix everything at once. Follow this prioritized plan:

Week 1: Critical Fixes

  • • Set up SPF, DKIM, and DMARC if missing
  • • Remove all hard bounces from your list
  • • Check and delist from any blacklists
  • • Enable feedback loops with major ISPs

Week 2: List Cleanup

  • • Run your entire list through email verification
  • • Remove or suppress disposable and role addresses
  • • Segment unengaged subscribers (6+ months no opens)
  • • Enable real-time verification on signup forms

Week 3: Infrastructure

  • • Audit sending IPs and consider dedicated IP
  • • Separate transactional and marketing streams
  • • Review and optimize email templates
  • • Test emails with mail-tester.com

Week 4: Monitoring Setup

  • • Set up automated blacklist monitoring
  • • Configure DMARC report analysis
  • • Create alerts for bounce rate spikes
  • • Schedule quarterly list re-verification

Automate Your Deliverability Monitoring

Kawaa provides email verification, blacklist monitoring, and DMARC analysis in one platform. Stop manually checking dozens of tools—get alerts when something needs attention.

Start Your Free Audit

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