Prompt Library

Marketing ROI

Email Deliverability Audit Checklist

Fixes technical issues killing your email open rates and costing sales.

1. Current State Assessment

  1. Ask the user about their email metrics—open rate, click rate, bounce rate, spam complaint rate, and list size.
    • Example: "What are your current email metrics: open rate %, click rate %, bounce rate %, spam complaints, and total subscribers?"
  2. Ask the user what email platform they use and how they send emails—ESP (Mailchimp, SendGrid, etc.), frequency, and volume.
    • Example: "Which email service do you use, how often do you send, and what's your typical send volume per campaign?"
  3. Ask the user about list management practices—how do you collect emails, permission-based, purchased lists, inactive subscriber handling.
    • Example: "How do you build your list—opt-in forms, purchased, scraped? Do you clean inactive subscribers?"
  4. Ask the user if they've had deliverability issues—landing in spam, blacklist warnings, or sudden metric drops.
    • Example: "Have you noticed emails going to spam, been blacklisted, or seen sudden drops in open rates?"

2. Technical Authentication Audit

SPF (Sender Policy Framework):

  • What it is: DNS record that specifies which servers can send email from your domain
  • Check: Query DNS for SPF record
  • Fix: Add or update SPF record to include your ESP's sending servers
  • Syntax: v=spf1 include:_spf.google.com include:sendgrid.net ~all

DKIM (DomainKeys Identified Mail):

  • What it is: Cryptographic signature proving email wasn't tampered with
  • Check: Send test email, check headers for DKIM-Signature
  • Fix: Configure DKIM keys in ESP and add DNS records
  • Validation: Use mail-tester.com or similar to verify

DMARC (Domain-based Message Authentication):

  • What it is: Policy telling receivers what to do with failed SPF/DKIM
  • Check: Query DNS for DMARC record
  • Fix: Add DMARC policy (start with p=none for monitoring, escalate to p=quarantine or p=reject)
  • Example: v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com

Custom Domain Sending:

  • Issue: Sending from generic ESP domain (e.g., mailchimp.com) hurts deliverability
  • Fix: Configure custom sending domain (mail.yourdomain.com)
  • Benefit: Better reputation control, branded sender

BIMI (Brand Indicators for Message Identification):

  • What it is: Display brand logo in inbox (Gmail, Yahoo support)
  • Requirements: DMARC enforcement + verified logo
  • Implementation: Advanced, but improves brand recognition

3. List Quality & Hygiene

Permission & Consent:

  • ✓ Only email people who explicitly opted in
  • ✓ Double opt-in for highest quality (confirmation email)
  • ✗ Never use purchased, scraped, or rented lists
  • ✗ Don't add people without permission

List Cleaning Practices:

  • Remove hard bounces immediately (invalid addresses)
  • Remove soft bounces after 3-5 failures (temporary issues)
  • Segment out inactive subscribers (no open/click in 90-180 days)
  • Send re-engagement campaign before removing inactives
  • Scrub spam trap addresses (use validation service)

Email Validation:

  • Use email verification service (NeverBounce, ZeroBounce, etc.)
  • Validate at signup (real-time API check)
  • Batch validate existing list
  • Remove: Invalid syntax, disposable emails, role addresses (info@, admin@)

Engagement-Based Segmentation:

  • Highly engaged: Opened/clicked in last 30 days
  • Moderately engaged: Opened in last 90 days
  • Low engagement: No action in 90-180 days
  • Inactive: No action in 180+ days

Send more frequency to engaged, less to low-engagement to protect sender reputation.

4. Content & Sending Best Practices

Spam Trigger Avoidance:

  • Subject lines: Avoid ALL CAPS, excessive punctuation!!!, spammy words (FREE, URGENT, $$$)
  • Body content: Balance text and images (not image-only), avoid suspicious links
  • Formatting: Use standard fonts, avoid all-red text, excessive formatting
  • Links: Use HTTPS, avoid URL shorteners if possible, don't hide links

Content Quality Signals:

  • Clear, valuable subject line (not clickbait)
  • Personalization (use recipient name, relevant content)
  • Mobile-responsive design
  • Easy unsubscribe link (required by law, helps deliverability)
  • Physical mailing address (required by CAN-SPAM)
  • Consistent from name and address

Sending Patterns:

  • Warm up new sending domain/IP gradually (start low volume, increase over weeks)
  • Consistent send schedule (not sporadic)
  • Avoid sudden volume spikes (looks like spam burst)
  • Monitor send time (business hours typically better for B2B)

List Segmentation:

  • Don't send every email to entire list
  • Segment by interest, behavior, lifecycle stage
  • Targeted emails get better engagement = better deliverability

5. Reputation Monitoring

Sender Score (0-100):

  • Check at senderscore.org
  • Score >80: Good, 70-80: Needs improvement, <70: Poor
  • Factors: Bounce rate, spam complaints, blacklist status, engagement

Blacklist Monitoring:

  • Check major blacklists: Spamhaus, SURBL, Barracuda
  • Tool: mxtoolbox.com/blacklists.aspx
  • If blacklisted: Identify cause, fix issue, request delisting

Inbox Placement Testing:

  • Use tool like GlockApps or Email on Acid
  • Sends test email to multiple providers (Gmail, Outlook, Yahoo, etc.)
  • Shows where email lands: Inbox, Promotions tab, Spam
  • Provides deliverability score and recommendations

Engagement Metrics:

  • Open rate: Industry benchmark 15-25% (varies by niche)
  • Click rate: 2-5% typical
  • Bounce rate: <2% good, >5% concerning
  • Spam complaint rate: <0.1% (>0.3% is red flag)
  • Unsubscribe rate: <0.5% per send

6. Deliverability Optimization Plan

Immediate Actions (Week 1):

  • Verify SPF, DKIM, DMARC are configured
  • Remove hard bounces and obvious invalids
  • Check if blacklisted, request removal if needed
  • Add clear unsubscribe link if missing

Short-term Fixes (Month 1):

  • Validate entire email list
  • Segment out inactive subscribers
  • Send re-engagement campaign
  • Audit recent emails for spam triggers
  • Implement double opt-in for new signups

Ongoing Optimization:

  • Monitor sender score weekly
  • Clean list monthly (remove bounces, inactives)
  • A/B test subject lines to improve engagement
  • Segment sends for relevance
  • Track inbox placement monthly

Advanced Tactics:

  • Dedicated IP address (if sending high volume >100K/month)
  • Custom sending domain with warm-up
  • Implement BIMI for logo in inbox
  • Sunset inactive subscribers aggressively

7. Deliverables

Audit Report:

  • Current authentication status (SPF/DKIM/DMARC)
  • List quality assessment
  • Engagement metrics vs. benchmarks
  • Blacklist status
  • Sender score
  • Identified issues and severity

Action Plan:

  • Prioritized fixes with step-by-step instructions
  • Technical configurations needed
  • List cleaning recommendations
  • Content optimization tips
  • Timeline and owner for each task

Monitoring Dashboard:

  • Key metrics to track weekly/monthly
  • Alert thresholds (when to investigate)
  • Benchmark comparisons
  • Trend tracking

Best Practices Guide:

  • Ongoing list hygiene procedures
  • Content creation guidelines
  • Sending frequency recommendations
  • Compliance requirements

Present comprehensive deliverability audit with technical assessment, actionable fixes, and ongoing optimization framework to improve inbox placement and email ROI.