How to Calculate Email Deliverability Score
Email deliverability score measures how effectively your emails reach recipients' inboxes. It's based on delivery rate, bounce rate, and spam complaint rate.
The Deliverability Score Formula
Deliverability Rate = (Emails Delivered ÷ Emails Sent) × 100
Bounce Rate = (Emails Bounced ÷ Emails Sent) × 100
Spam Rate = (Spam Complaints ÷ Emails Sent) × 100
Understanding Deliverability Metrics
- Deliverability Rate: % of emails that reached mailboxes (target: 95%+)
- Bounce Rate: % of emails that couldn't be delivered (target: below 2%)
- Spam Complaint Rate: % marked as spam (target: below 0.1%)
- Open Rate: % who opened delivered emails (indicator of engagement)
Deliverability Score Ranges
- 90-100: Excellent sender reputation, emails reach inbox consistently
- 80-89: Good performance, minor improvements needed
- 70-79: Fair, address bounce and spam issues soon
- Below 70: Poor, urgent action required to avoid blacklisting
How to Improve Email Deliverability
- Clean Your List: Remove invalid emails, use email verification tools
- Use Double Opt-In: Verify subscribers actually want your emails
- Authenticate Your Domain: Set up SPF, DKIM, and DMARC records
- Warm Up New IPs: Gradually increase send volume on new sending IPs
- Avoid Spam Triggers: Don't use all caps, excessive punctuation, spam words
- Maintain Engagement: Remove inactive subscribers (90+ days no opens)
- Monitor Blacklists: Check if your domain/IP is blacklisted
- Provide Easy Unsubscribe: Make it simple to opt out legally
Why Sender Reputation Matters
Email providers (Gmail, Outlook, etc.) assign sender reputation scores based on your history. Poor reputation means your emails go to spam, even if recipients want them. Factors affecting reputation:
- Bounce rate (invalid addresses hurt reputation)
- Spam complaint rate (most damaging factor)
- Engagement (opens, clicks, replies boost reputation)
- Authentication (SPF, DKIM, DMARC required)
- Sending consistency (sudden volume spikes hurt reputation)