Email Deliverability Checklist — 20 Things to Check Before You Send

Email deliverability is the ability to successfully deliver emails to recipients' inboxes rather than spam folders or blocked entirely. Achieving high deliverability requires attention to technical setup, list quality, content optimization, and sender reputation management.

This comprehensive checklist covers the 20 essential elements you must verify before any major email campaign. Use it as a pre-flight checklist to ensure your emails reach their intended destination.

Technical Infrastructure (Checks 1-6)

1. SPF Record Configured

SPF (Sender Policy Framework) specifies which mail servers can send email on behalf of your domain.

What to Check:

• TXT record exists in DNS
• Includes all sending IPs/services
• Syntax is valid
• Record isn't too long (10 DNS lookups max)

Example SPF Record: ``` v=spf1 include:_spf.google.com include:spf.mailgun.org include:sendgrid.net ~all ```

Tools: [SPF checker tools], MXToolbox, Google Admin Toolbox

Status: ☐ Verified

2. DKIM Authentication Enabled

DKIM (DomainKeys Identified Mail) adds a digital signature to verify email authenticity.

What to Check:

• DKIM key generated in email platform
• Public key published in DNS
• Key length adequate (2048-bit recommended)
• Selector properly configured

Verification:

• Send test email
• Check headers for DKIM-Signature
• Verify "dkim=pass" in authentication results

Tools: [DKIM checker tools], email header analyzers

Status: ☐ Verified

3. DMARC Policy Published

DMARC (Domain-based Message Authentication) tells receivers how to handle authentication failures.

What to Check:

• DMARC record exists
• Policy is appropriate (start with p=none, progress to p=quarantine or p=reject)
• RUA tag for reports configured
• Alignment modes set correctly

Example DMARC Record: ``` v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com; pct=100 ```

Tools: [DMARC checker tools], DMARCian, Valimail

Status: ☐ Verified

4. Reverse DNS (PTR) Configured

PTR records map your IP address back to your domain, verifying legitimacy.

What to Check:

• PTR record exists for sending IP
• Points to valid hostname
• Matches forward DNS lookup
• Not generic or missing

Verification: ```bash nslookup <your-ip-address>

Should return your hostname

```

Tools: MXToolbox, ViewDNS.info

Status: ☐ Verified

5. Custom Domain Tracking Links

Using your own domain for tracking links improves trust and deliverability.

What to Check:

• Custom tracking domain configured
• SSL certificate active
• CNAME records properly set
• Links render correctly in tests

Setup:

• Configure in ESP settings
• Add CNAME: clicks.yourdomain.com → tracking.esp.com
• Verify SSL

Status: ☐ Verified

6. Dedicated IP vs. Shared IP Strategy

Your IP reputation significantly impacts deliverability.

Shared IP:

• ☐ Appropriate for: Low volume (<50k/month), new senders, irregular sending
• ☐ ESP manages reputation
• ☐ Less control, more hands-off

Dedicated IP:

• ☐ Appropriate for: High volume (100k+/month), consistent sending, reputation control needed
• ☐ Requires proper warm-up
• ☐ Full reputation ownership

Verify: Your IP isn't blacklisted

Tools: MXToolbox, MultiRBL, Barracuda Reputation

Status: ☐ Verified

List Quality (Checks 7-11)

7. List Hygiene Performed

Clean lists are essential for good deliverability.

What to Check:

• ☐ Hard bounces removed (<2% rate)
• ☐ Soft bounces monitored
• ☐ Duplicate emails eliminated
• ☐ Role-based emails assessed (info@, admin@)
• ☐ Spam traps removed
• ☐ Typos corrected (gmial.com → gmail.com)

Verification:

• Run list through [email verification tool]
• Check for syntax errors
• Validate domains
• Remove toxic addresses

Status: ☐ Cleaned

8. Permission Confirmed

Only email people who expect your messages.

What to Check:

• ☐ Double opt-in for new subscribers
• ☐ Explicit consent documented
• ☐ No purchased lists
• ☐ No scraped emails
• ☐ Re-engagement for inactive subscribers

Warning Signs:

• Sudden list growth
• Unknown list sources
• High spam complaint rates
• Low engagement from new subscribers

Status: ☐ Verified

9. Engagement Segmentation

Segment based on engagement to optimize reputation.

What to Check:

• ☐ Highly engaged (opened last 30 days) → Priority sending
• ☐ Moderately engaged (opened last 90 days) → Standard sending
• ☐ Low engagement (opened last 6 months) → Reduced frequency
• ☐ Inactive (no opens 6+ months) → Re-engagement or suppression

Strategy:

• Send to engaged segments first
• Good engagement builds reputation
• Then expand to less engaged

Status: ☐ Segmented

10. Suppression Lists Maintained

Never email people who've opted out or complained.

What to Check:

• ☐ Unsubscribes automatically suppressed
• ☐ Hard bounces suppressed
• ☐ Spam complaints suppressed
• ☐ List-unsubscribe headers present
• ☐ One-click unsubscribe working

Legal Requirements:

• Honor unsubscribes within 10 days (CAN-SPAM)
• Immediate suppression recommended
• Maintain suppression records

Status: ☐ Updated

11. List Age Considered

Email lists decay approximately 22% per year.

What to Check:

• ☐ Recency of email collection
• ☐ Regular verification schedule
• ☐ Re-confirmation for old imports
• ☐ Bounce handling processes

Actions for Old Lists:

• Verify before sending
• Send re-confirmation campaign
• Expect higher bounce rates
• Warm up gradually

Status: ☐ Assessed

Content Optimization (Checks 12-15)

12. Spam Trigger Words Avoided

Certain words and phrases trigger spam filters.

High-Risk Words to Minimize:

• FREE!!!, Act Now, Limited Time
• Cash, Prize, Winner, Million Dollars
• Viagra, Weight Loss, Debt
• All caps, excessive punctuation!!!
• Excessive emojis 🎉🎉🎉

What to Check:

• ☐ Subject line scanned
• ☐ Body content reviewed
• ☐ Spam score checked (aim for <5)
• ☐ Balance promotional vs. value content

Tools: Mail-Tester, GlockApps, SubjectLine.com

Status: ☐ Reviewed

13. Text-to-Image Ratio Balanced

Image-heavy emails often land in spam.

What to Check:

• ☐ Minimum 60% text, 40% images
• ☐ Alt text on all images
• ☐ No single large image as entire email
• ☐ Images hosted on reputable domains
• ☐ Image file sizes optimized

Best Practice:

• Key message in text, not images
• Images enhance, don't replace content
• Test with images blocked

Status: ☐ Balanced

14. Links Verified

Broken or suspicious links hurt deliverability.

What to Check:

• ☐ All links functional
• ☐ No URL shorteners (bit.ly, etc.)
• ☐ Destination domains reputable
• ☐ HTTPS where possible
• ☐ No link farms or suspicious sites
• ☐ UTM parameters properly formatted

Warning Signs:

• Redirect chains
• Blacklisted destination domains
• Mismatched link text vs. URL

Status: ☐ Checked

15. Email Format Validated

Proper formatting ensures deliverability and display.

What to Check:

• ☐ Valid HTML structure
• ☐ Proper doctype
• ☐ Inline CSS (for email clients)
• ☐ Table-based layout (for Outlook)
• ☐ Mobile-responsive design
• ☐ Plain text version included
• ☐ Character encoding UTF-8

Testing:

• Litmus or Email on Acid for rendering
• Multiple clients (Gmail, Outlook, Apple Mail)
• Mobile devices
• Dark mode compatibility

Status: ☐ Validated

Sender Reputation (Checks 16-18)

16. Sending Domain Reputation Good

Your domain reputation is portable across email providers.

What to Check:

• ☐ Google Postmaster Tools setup
• ☐ Microsoft SNDS enrollment
• ☐ Yahoo/Fahoo sender monitoring
• ☐ No recent blacklistings
• ☐ Consistent sending volume
• ☐ Gradual volume increases

Reputation Factors:

• Spam complaint rate (<0.1%)
• Bounce rate (<2%)
• Engagement rates (opens, clicks)
• Sending consistency

Tools: [email deliverability checkers], Google Postmaster, Return Path

Status: ☐ Monitored

17. IP Reputation Monitored

Your sending IP reputation affects deliverability.

What to Check:

• ☐ IP not on major blacklists
• ☐ Sender Score above 80
• ☐ Low complaint rates
• ☐ Proper warm-up completed
• ☐ Consistent sending patterns

Blacklist Checks:

• Spamhaus
• Barracuda
• SpamCop
• SURBL
• Invaluement

Tools: MXToolbox MultiRBL, Sender Score

Status: ☐ Checked

18. Authentication Alignment Verified

DMARC requires alignment between visible and actual sending domains.

What to Check:

• ☐ SPF alignment (Envelope From = Header From domain)
• ☐ DKIM alignment (d= tag matches Header From)
• ☐ No forwarding breaks authentication
• ☐ Third-party senders properly authorized

Types of Alignment:

• Strict: Exact domain match required
• Relaxed: Subdomain matches acceptable

Verification: Check Authentication-Results headers

Status: ☐ Verified

Sending Practices (Checks 19-20)

19. Volume and Timing Optimized

Smart sending patterns improve reputation.

What to Check:

• ☐ Volume within ISP limits
• ☐ Gradual ramp-up for large campaigns
• ☐ Consistent sending schedule
• ☐ Optimal send time for audience
• ☐ Throttling configured if needed

ISP Limits:

• Gmail: 500/day (personal), 2,000/day (Workspace)
• Outlook: 300/day (initial), 10,000/day (established)
• Yahoo: 100/hour (initial), 500/hour (established)

Best Practices:

• Spread large sends over time
• Avoid sudden volume spikes
• Send during business hours
• Respect recipient time zones

Status: ☐ Planned

20. Feedback Loops Registered

Feedback loops notify you when recipients mark emails as spam.

What to Check:

• ☐ Registered with major ISPs
• ☐ Spam complaints monitored
• ☐ Automatic suppression configured
• ☐ Complaint analysis process

Major FBLs:

• Google (via Postmaster Tools)
• Microsoft (JMRP)
• Yahoo
• AOL
• Cloudmark
• Barracuda

Action on Complaints:

• Immediately suppress complainer
• Analyze complaint causes
• Adjust content or targeting
• Consider list source quality

Status: ☐ Registered

Pre-Send Final Verification

Test Checklist

Before sending to your full list:

• ☐ Send to seed list (Gmail, Outlook, Yahoo, Apple Mail)
• ☐ Check inbox placement in each
• ☐ Verify spam folder placement
• ☐ Test all links
• ☐ Check image rendering
• ☐ Review on mobile devices
• ☐ Confirm unsubscribe works
• ☐ Validate personalization tokens

Tools for Testing

Inbox Placement:

• GlockApps
• Mail-Tester
• Litmus
• Email on Acid
• Pivotal Veracity

Header Analysis:

• Google Admin Toolbox
• MXToolbox Header Analyzer
• Mailheader.org

Post-Send Monitoring

Metrics to Watch

Actions Based on Results

If metrics are good:

• Continue current practices
• Gradually increase volume
• Maintain monitoring

If metrics show warnings:

• Investigate causes
• Review content and targeting
• Consider list cleaning
• Reduce volume temporarily

If metrics are critical:

• Pause campaigns immediately
• Investigate blacklistings
• Clean list thoroughly
• Review authentication
• Consider reputation repair

Frequently Asked Questions About Email Deliverability

What is email deliverability? Email deliverability is the ability to deliver emails to recipients' inboxes rather than spam folders or blocked entirely. It encompasses technical setup, list quality, content, and sender reputation.

How do I check my email deliverability? Use tools like Mail-Tester, GlockApps, or seed list testing. Check authentication with [SPF checker tools], [DKIM checker tools], and [DMARC checker tools]. Monitor Google Postmaster Tools for domain reputation.

What's a good email deliverability rate? Aim for 95%+ delivery rate (not bouncing). Inbox placement rates vary but should be 85%+ for engaged lists. New or cold lists may see 70-80% initially.

How long does it take to fix deliverability issues? Minor issues: 1-2 weeks. Major reputation damage: 4-12 weeks. Blacklist removal: Days to weeks depending on the list. Consistent good practices rebuild reputation over time.

Do I need all three authentication methods (SPF, DKIM, DMARC)? Yes, for optimal deliverability. SPF and DKIM verify sender identity. DMARC provides policy and reporting. Together they significantly improve trust with ISPs.

Why do my emails go to spam? Common causes: missing authentication, poor list quality, spammy content, bad sender reputation, sudden volume changes, or blacklistings. Systematically check each element of this checklist.

How often should I check deliverability? Before every major campaign, monthly for ongoing monitoring, and immediately if metrics drop. Set up automated monitoring through Google Postmaster and similar tools.

Conclusion: Deliverability as Ongoing Discipline

Email deliverability isn't a one-time setup — it's an ongoing discipline requiring regular attention. This 20-point checklist provides a systematic approach to ensuring your emails reach inboxes consistently.

Save this checklist and run through it before every major campaign. Track your metrics, investigate anomalies promptly, and maintain the technical and list hygiene standards that protect your sender reputation.

Remember: every email that reaches the inbox is an opportunity. Every email that hits spam is a wasted effort. The time invested in deliverability pays dividends in campaign performance and business results.