Email Marketing Metrics That Matter: Beyond Open Rates

Open rates and click rates are just the beginning. To truly understand email performance and deliverability, you need to track metrics that actually predict long-term success. Here are the metrics that matter in 2025.

Why Most Marketers Track the Wrong Metrics

Many email marketers obsess over open rates while ignoring the metrics that actually impact revenue and deliverability. Open rates can be misleading (thanks Apple Mail Privacy Protection), and high click rates mean nothing if those emails never reached the inbox.

Deliverability Metrics (The Foundation)

These metrics determine whether your emails reach inboxes at all. Master these before worrying about opens and clicks.

1. Inbox Placement Rate (IPR)

What it is: Percentage of emails that land in the inbox (not spam, not promotions tab).

Goal: 95%+ to inbox

How to measure: Seed list testing tools or Google Postmaster Tools

2. Bounce Rate

What it is: Percentage of emails that couldn't be delivered.

Types:

• Hard bounces: Invalid email addresses (remove immediately)
• Soft bounces: Temporary issues (full inbox, server down)

Goal: Under 2% total, under 0.5% hard bounces

3. Spam Complaint Rate

What it is: Percentage of recipients who marked your email as spam.

Goal: Under 0.1% (0.3% is dangerous, 0.5% is disaster)

Impact: This metric kills sender reputation faster than anything else.

4. Sender Reputation Score

What it is: Your reputation with ISPs, scored 0-100.

Goal: Above 80 (90+ is excellent)

How to check: Sender Score, Google Postmaster Tools, Microsoft SNDS

Engagement Metrics (What ISPs Watch)

Gmail, Outlook, and Yahoo track how recipients interact with your emails. Strong engagement improves deliverability.

5. Open Rate

What it is: Percentage of delivered emails that were opened.

Benchmarks:

• 20-30%: Average
• 30-40%: Good
• 40%+: Excellent

Caveat: Apple Mail Privacy Protection inflates open rates by auto-loading images.

6. Click Rate

What it is: Percentage of delivered emails where recipient clicked a link.

Benchmarks:

• 2-3%: Average
• 3-5%: Good
• 5%+: Excellent

7. Click-to-Open Rate (CTOR)

What it is: Percentage of email opens that resulted in clicks.

Formula: (Unique clicks ÷ Unique opens) × 100

Why it matters: Shows if your content delivers on your subject line's promise.

Benchmarks:

• 10-15%: Average
• 15-25%: Good
• 25%+: Excellent

8. Reply Rate

What it is: Percentage of recipients who replied to your email.

Why it matters: Gmail especially loves replies. Conversation signals genuine engagement.

Goal: 1%+ (higher for cold emails)

List Health Metrics

9. List Growth Rate

Formula: [(New subscribers - Unsubscribes) ÷ Total subscribers] × 100

Goal: Positive growth month-over-month

10. Unsubscribe Rate

What it is: Percentage of recipients who unsubscribed.

Goal: Under 0.5%

Note: Unsubscribes aren't necessarily bad—they clean your list. Spam complaints are the real problem.

11. Email List Churn Rate

What it is: Rate at which email addresses become inactive.

Why it matters: 25-30% of email lists decay annually. You need to replace lost subscribers.

Revenue Metrics

12. Conversion Rate

What it is: Percentage of recipients who completed your desired action (purchase, signup, etc.).

Varies by: Industry, list quality, offer

13. Revenue Per Email

Formula: Total revenue ÷ Number of emails delivered

Why it matters: This is the ultimate metric. You can have low open rates but high revenue per email.

14. Customer Lifetime Value (from Email)

What it is: Total revenue a subscriber generates over their lifetime.

Why it matters: A smaller, highly engaged list can be more valuable than a large, unengaged one.

Advanced Metrics

15. Read Time

What it is: How long recipients spend reading your email.

Why it matters: Gmail tracks this. Longer read time = more valuable content.

16. Forward Rate

What it is: Percentage of recipients who forwarded your email.

Why it matters: Forwarding is the strongest engagement signal. It grows your audience organically.

How to Track These Metrics

• Email Service Provider: Most metrics built-in
• Google Postmaster Tools: Gmail-specific deliverability
• Microsoft SNDS: Outlook deliverability
• Sender Score: Overall sender reputation
• Seed testing services: Inbox placement across providers
• SPAMRUN: Test emails before sending

What to Optimize First

Work in this order:

• 1. Deliverability: Get emails to inbox first
• 2. Opens: Write better subject lines
• 3. Clicks: Improve content and CTAs
• 4. Conversions: Optimize landing pages
• 5. Revenue: Increase customer lifetime value