Cold Email Performances: Metrics to Measure and Improve Them

"If it can’t be measured, it can’t be improved." Go ahead, tell us you’ve never heard this phrase before!

Well, it’s especially true when it comes to cold emailing. However, not all metrics are created equal. Some can even be misleading if analyzed without the right context.

This article aims to help you make sense of cold email metrics—what they mean and how to use them wisely.

⚡ Let’s dive in!

Understanding Key Email Metrics for Cold Email Performances 

First, let’s distinguish between primary and secondary KPIs. Primary KPIs are metrics directly tied to the main objectives of your campaign. They measure the outcomes you’re aiming for, such as conversions, engagement, or overall performance.

Examples of primary KPIs in cold emailing:

• Open Rate

• Reply Rate

• Conversion Rate

Secondary KPIs, on the other hand, help you better understand the results of your primary KPIs. They provide context about the health of your campaign.

Examples of secondary KPIs in cold emailing:

• Forward Rate

• Bounce Rate

• Unsubscribe Rate

It’s also essential to understand the difference between cold emailing and traditional email marketing.

A cold email is sent to prospects who don’t know you yet, with the goal of creating a first connection. Traditional email marketing, by contrast, targets an already engaged audience, such as subscribers or customers.

This fundamental difference influences both the metrics you use and how you interpret them.

For example: in traditional email marketing, open and click-through rates are major indicators of engagement. In cold emailing, these metrics are less meaningful unless they lead to replies or qualified conversations.

These so-called “vanity metrics,” while useful, don’t provide a complete picture of true performance. That’s why their analysis must always be correlated with other metrics to gain actionable insights.

Click-Through Rates (CTR and CTOR)

What Are CTR and CTOR?

Most of the information you’ll find online about click-through rates doesn’t differentiate between CTR and CTOR.

CTR (Click-Through Rate) measures the percentage of recipients who clicked on a link in your email, relative to the total number of emails sent.

CTOR (Click-to-Open Rate) measures the percentage of recipients who clicked on a link, relative to the total number of emails opened.

🧮 The formula for both is nearly identical: Divide the number of unique clicks by the number of emails sent/opened, then multiply by 100.

Example:If you send 1,000 emails and receive 50 clicks, your CTR is:

(50 ÷ 1,000) × 100 = 5%

CTR helps you evaluate the overall performance of the campaign.

CTOR is more useful for assessing the effectiveness of your content or calls-to-action.

💡 Tip from Mail Merge for Gmail: Segment your email list based on recipient behavior and interests. Highly personalized content can boost both your CTR and CTOR by 20% to 40%.

What Is a Good Click-Through Rate?

According to a HubSpot benchmark study, the average CTR across all industries is 3.1%.

Achieving or surpassing 5% is considered excellent performance.

CTR Averages by Industry

Below is a table showing average CTRs by industry, based on cold email campaigns sent using our tool:

The average CTR across these industries is 6.04% for 2024. The secret? Well-optimized campaigns using the right tools and effective email copywriting techniques.

Email Open Rates

What Are Email Open Rates?

The open rate measures how many of your emails were opened compared to the total number of emails sent.

🧮 Email Open Rate Formula: (Number of emails opened ÷ Number of emails sent) × 100

Example: If you send 1,000 emails and 300 of them are opened, your open rate is:

(300 ÷ 1,000) × 100 = 30%

In cold emailing, the open rate provides insights into:

• The relevance of your email subject lines and pre-headers.

• The effectiveness of your segmentation and personalization.

• The quality of your email list (e.g., avoiding invalid or disengaged addresses).

💡 Expert Tip: Some tools track total email opens rather than unique opens, which can distort your analysis. With Mail Merge for Gmail, when an email is opened, its status changes from “Sent” to “Read,” ensuring more accurate data.

What Is a Good Open Rate for Email?

According to a HubSpot study, the average email open rate across all industries is 22.04%.

On average, an open rate between 15% and 25% is considered acceptable for cold email campaigns.

🧐 What about open rates of 60%? We must admit, dear readers, that we’ve been surprised by some articles published by less-than-scrupulous SaaS vendors claiming miraculous open rates of 60%.

Here’s how to explain such figures:

It’s either false!

Or, it’s true—but only under very specific conditions:

• The audience is ultra-targeted.

• The campaign is sent internally (to employees, existing partners).

• It’s tied to high-value promotions.

Email Open Rate Averages by Industry

At Mail Merge for Gmail, we value transparency.

Below is a table showing average open rates by industry, based on cold email campaigns sent using our tool:

The average open rate across these industries is 26.04% for 2024.

Reply Rate

The Reply Rate measures the percentage of recipients who responded to your email, compared to the total number of emails sent.

Unlike the open rate or CTR, the reply rate directly measures engagement that triggers an interaction.

🧮 Reply Rate Formula: (Total number of replies ÷ Total number of emails sent) × 100

Example: If you send 1,000 emails and receive 50 replies, your reply rate is:

(50 ÷ 1,000) × 100 = 5%

The average reply rate for cold emailing varies depending on the industry, the quality of your prospect list, and the level of personalization in your messages. Here are some benchmarks:

• Generic campaigns (little to no personalization): 1%–3%.

• Segmented campaigns (with basic personalization): 5%–10%.

• Hyper-personalized campaigns (leveraging specific data about the prospect): Up to 20% in some B2B industries.

Thus, a reply rate above 10% is often considered a strong performance, especially in B2B sectors.

💡 Tip from Mail Merge for Gmail: Correlate your open rate with your reply rate: If your open rate is high (>30%) but your reply rate is low (<3%), this indicates an issue with your content or call-to-action. If both your open rate (<20%) and reply rate are low, your subject line or email list likely needs optimization.

Conversion Rate 

The Conversion Rate measures the percentage of recipients who performed a desired action after interacting with your email. This is the ultimate indicator of your campaign’s performance, as it reflects its direct impact on your business results.

🧮 Conversion Rate Formula: (Total number of conversions ÷ Total number of emails sent) × 100

Example: You send 1,000 emails, 50 people click your link (CTR), and 10 of them complete your form or make a purchase. Your conversion rate is:

(10 ÷ 1,000) × 100 = 1%

A conversion rate above 2% is considered solid. A rate higher than 5% is excellent in most B2B industries.

💡 Tip from Mail Merge for Gmail: Optimize your conversion rate by reducing the number of steps required to convert. For example, if your goal is to schedule a meeting, include a link to a tool like Calendly directly in your email, enabling recipients to book instantly.

Bounce Rate 

The Bounce Rate represents the percentage of emails that could not be delivered to their recipients.

This metric is critical in cold emailing because a high bounce rate directly impacts your sender reputation. Over time, this creates a domino effect, reducing the deliverability of your future campaigns.

🧮 Bounce Rate Formula: (Number of undelivered emails ÷ Total number of emails sent) × 100

There are two main categories of email delivery failures:

• Hard Bounces (Permanent Errors) : These emails can never be delivered, often because the email address is invalid. These addresses should be immediately removed from your list.

• Soft Bounces (Temporary Errors):These emails may eventually be delivered, as the issue is temporary—for example, the recipient’s inbox is full, or there’s a server issue.

If your bounce rate exceeds 5%, this signals serious issues.

💡 Expert Tip: Regularly update your email list by removing inactive or outdated addresses to avoid bounces. With Mail Merge for Gmail, this process is straightforward. The tool integrates seamlessly with Google Sheets and Gmail, eliminating the need for third-party software.

Unsubscribe Rate

The Unsubscribe Rate is a key indicator of how relevant and acceptable your campaigns are to your recipients. A high unsubscribe rate reflects a mismatch between your message and your prospects’ interests.

🧮 Unsubscribe Rate Formula: (Number of unsubscribes ÷ Total number of emails sent) × 100

An unsubscribe rate above 1% is a red flag. If you notice this, it’s essential to analyze the causes!

👉 Our research is clear: The primary cause of high unsubscribe rates is email frequency. If you’re sending emails too often, that’s the first thing to address.

💡 Expert Tip: Always make it easy for recipients to unsubscribe. Including a dedicated unsubscribe link reduces the risk of being marked as spam and ensures a cleaner email list. Mail Merge for Gmail offers a built-in option to create unsubscribe links, helping you stay compliant and professional.

Forward Rate

The Forward Rate measures the percentage of emails forwarded by your recipients to others. This KPI is often underestimated, but it’s a powerful indicator of the virality and interest generated by your messages.

🧮 Forward Rate Formula: (Number of forwards ÷ Total number of emails sent) × 100

Forward rates in cold emailing are typically low because recipients are often cold prospects. A forward rate above 1% is considered strong.

💡 Tip from Mail Merge for Gmail: Use direct sharing buttons to make forwarding easier for recipients.

How to Optimize Your Email Campaign Performance for Better Results 

Now that you’ve understood the essential metrics and goals to achieve, let’s dive into key strategies to create highly effective cold email campaigns.

Nail the Basics

Personalization

Personalization is the ultimate key to cold emailing: talk about your prospect before you talk about your offer. Here’s how:

• Research pain points and the prospect’s worldview to understand them better.

• Use precise data (industry, role, location) to show that you understand the recipient’s needs.
  Example: “As a Marketing Manager in Paris, here’s how we can help you…”

• Mention a recent event to show genuine interest.

We’ve outlined a detailed methodology with examples in our article “How to write a cold email”.

Subject Lines

A compelling subject line can significantly boost your open rates. For inspiration, check out our guide to effective email subject lines.

Here’s a quick summary of 5 best practices:

1. Keep your subject line short and sweet.

2. Write personalized subject lines (“How to solve {{painPoint}} in 30 days?”).

3. Ask a question – if relevant (“Do you need help with {{painPoint}}?”).

4. Keep your subject line casual.

5. Add urgency (“A special gift just for you, {{firstname}}.”).

Timing

There’s no magic formula—just analysis and A/B testing.

✔️ Analyze your audience’s habits. For example, in B2B, emails sent on Tuesday mornings or Wednesday afternoons often achieve higher open rates.

✔️ Identify key timing windows. Consider when your target audience is most likely to be looking for solutions (e.g., end of the year for budget planning, beginning of the quarter for new projects).

✔️ Adjust for time zones if you’re targeting multiple regions. Schedule emails to send at the optimal time for each segment.

Mobile Optimization

Above all, don’t sabotage your efforts with a technical error. Make sure your emails display properly on mobile devices, as over 60% of emails are opened on smartphones today.

Keep subject lines short and place critical information above the fold (visible without scrolling). Think mobile-first to ensure a seamless experience!

Master the Art of Follow-Ups 

Follow-ups are a critical step in cold emailing: they can transform a cold prospect into a qualified opportunity. Yet, most businesses fail to get them right.

When to Follow Up and How Often

✔️ Wait 3 to 5 days for the first follow-up. Subsequent follow-ups can be spaced 7 to 10 days apart to avoid irritating your prospect.

✔️ An effective campaign includes 3 to 5 follow-ups. Sending fewer may mean missed opportunities; sending more can exhaust your prospects.

Writing Techniques for an Effective Follow-Up

✔️ Refer to a key point from your first message to show that your follow-up isn’t generic.
Example: “As mentioned in my previous email, I believe our solution could help you [solve a specific problem].”

✔️ Adjust your tone: If the prospect hasn’t responded to multiple emails, a more direct or humorous tone can sometimes re-engage their interest.
Example: “Maybe my previous email got lost in the pile? 😊 Here’s a quick reminder.”

✔️ Use clear and engaging calls-to-action:
Examples:

• “Do you have 15 minutes this week to discuss this? Here’s my calendar: [Calendly link].”

• “Is this a priority for your company at the moment?”

Keep Your Email List Clean and Up-to-Date 

A high-quality email list is essential to ensure deliverability and optimize your campaigns : 

1. Remove inactive addresses to avoid bounces and maintain a good sender reputation.

2. Regularly review and verify your list to ensure all contacts are up-to-date.

3. Segment your contacts to personalize your messaging and boost engagement.

Pro Tips: Keeping a list warm is nice, but it also means you are reducing your audience. We recommend using tools like Snowball to leverage social networks and add blood to your mailing list.

For more insights on managing your email lists, check out our article on the best tools for cold emailing.

Conclusion

You now have all the tools you need to optimize your cold email campaigns. Start taking action today: analyze your recent campaigns, identify areas for improvement, and implement the strategies we’ve shared.

And if you’re ready to take it a step further, try Mail Merge for Gmail—the best app for cold email! Let’s make your cold emails work harder for you.