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Cold Email Optimization Guide
Yaro Y. avatar
Written by Yaro Y.
Updated over 5 months ago

For the seasoned professional running cold email campaigns, this guide delves into advanced strategies to amplify and perfect your results.

True mastery lies in the ability to perpetually refine and debug your cold email campaigns, distinguishing the virtuosos from the mere apprentices.

Launching a successful campaign might seem elementary, but don’t be fooled—it's a nuanced art.

It requires relentless tweaking and a myriad of tests. However, with this comprehensive guide and unwavering commitment, even you can achieve mastery.

In this chapter, we will touch on:

  1. Ensuring the technical setup is impeccable.

  2. Fine-tuning sending frequencies and warmup volumes for optimal performance.

  3. Crafting and enhancing your email copy to perfection.

  4. The nuances of Open Tracking and when it’s best to disable it.

  5. Elevating your lead quality to premium standards.

  6. Swiftly identifying and eliminating poor performers.

  7. KPI Optimization

Initial Checklist

Before diving into advanced optimization strategies, it's crucial to ensure that your technical setup is flawless and your foundation is solid.

Address the following issues before proceeding with the guide:

Verify Proper Setup of Email Accounts.
Ensure SPF, DKIM, and DMARC are correctly configured. For assistance, refer to our tech setup guides

Confirm Email Accounts are Warmed Up.
Emails should be warmed up for at least two weeks before launching cold email campaigns to boost open rates.

The reputation and age of your domain, along with your sending accounts, significantly impact deliverability.

Validate Your Lead Lists.
Unverified email lists result in non-existent addresses and bounces, which lower your open rates and harm your sending reputation. Avoid bounces at all costs by verifying your leads using our built-in email validation tool.

Utilize a Custom Tracking Domain.
Using a shared tracking domain diminishes deliverability. Employ a custom tracking domain to enhance performance. Here's a guide on how to set it up.

Ensure You’re Not on Blacklists.
Being on one or two blacklists may not severely impact your inbox rates, but multiple listings can render your domain useless.

Regularly check your blacklist status via third-party services like MXToolbox. If heavily blacklisted, consider replacing your domain and accounts.

Ensure Your Email Domain Points to a Real Website.
Point your email domain to your main business website using a CNAME record (with SSL) or redirect it to your main site.

For detailed guidance on setting up your domains and email accounts for cold email sending, refer to our Tech Setup Guide.

Optimizing Sending & Warmup Volumes

When launching cold email campaigns, the sending volume is a critical factor to consider. Understanding and optimizing your sending volumes can significantly impact your campaign's success.

Here’s a comprehensive breakdown:

  1. Daily Sending Volume:

    • Recommendation: Send approximately 50 emails per day per email account, inclusive of warm-up emails.

    • Split Between Cold and Warm-up Emails: Divide your daily quota evenly. For instance, send 25 cold emails and 25 warm-up emails per day per email account

  2. Balanced Approach:

    • Flexibility in Numbers: While these numbers provide a solid starting point, remember they are guidelines, not rigid rules. Adjustments can be made to optimize performance.

    • Reputation Management: Sending cold emails can hurt your reputation due to bounces and spam reports. Utilize a warm-up system like pipl.ai, which balances this by generating positive interactions, thus enhancing your sending reputation.

By meticulously managing your sending and warm-up volumes, you can maintain a high sending reputation and improve the overall effectiveness of your cold email campaigns.

Understanding and adjusting the balance between cold emails and warm-up emails can greatly influence your campaign's success. Here are some scenarios to illustrate how you can tweak your approach:

Scenario 1: Declining Open & Reply Rates

  • Current Setup: Sending 25 cold emails and 25 warm-up emails per day per account.

  • Adjustment: Reduce to 15 cold emails and increase to 35 warm-up emails per day per account.

    • Expected Outcome: This shift will help the warm-up system enhance your sending reputation, leading to improved results within a week or two.

  • Alternative Adjustment: For a more aggressive approach, send 5 cold emails and 45 warm-up emails per day, or pause cold emails completely.

    • Strategy: After one to two weeks, gradually reintroduce cold emails and monitor changes in results.

Scenario 2: Successful Campaign Performance

  • Current Setup: Sending 25 cold emails and 25 warm-up emails per day per account.

  • Adjustment: Increase to 30 cold emails and reduce to 20 warm-up emails per day per account.

    • Monitoring Period: Observe the impact over one to two weeks to see if the change yields positive results.

    • Further Adjustment: If successful, consider further increasing the ratio of cold emails.

Summary: While the recommended daily limit is 50 emails per account, there's considerable flexibility in adjusting the ratio of cold to warm-up emails based on your campaign's performance.

Regularly review your results and fine-tune the balance to optimize deliverability and effectiveness.

Lowering Your Sending Volume

Sometimes, achieving better results can be as simple as reducing the number of emails you send per account each day. While the recommended daily limit is 50 emails, experimenting with lower volumes can yield improvements, which you should monitor over the next couple of weeks.

To streamline this process, you can directly limit your account-specific sending volumes within the email account settings in pipl.ai.

By adjusting the daily campaign limit in your email account settings, you avoid the hassle of modifying each campaign individually. This ensures that no more than the specified number of emails will be sent out, simplifying your optimization efforts.

Optimizing Your Copy

Before diving into advanced optimization techniques, pause and read our comprehensive copywriting masterclass. This resource covers all the essentials of cold email copywriting, offering specific examples and strategies you can implement immediately.

Basics of Effective Email Copy

Testing Copies

A key aspect of optimizing your cold email copy is thorough testing. Instead of relying on intuition, test multiple approaches and identify the best-performing copies based on actual results.

Every decision in your cold email campaign should be data-driven, and the good news is that it's straightforward to gather data from cold emails. Simply start sending and monitor the outcomes.

With pipl.ai 's A/B testing feature, this process becomes incredibly simple. Here’s how to systematically approach cold email copy testing:

  1. Create Diverse Copies: Begin by crafting at least 5 completely different email copies. You can draw inspiration from the 40+ strategies outlined in our copywriting masterclass.

  2. Identify a Winner: Select the top-performing copy from these initial 5 and then write 5 different variations of this winning copy.

  3. Test Variations: From these variations, identify the new top performer and increase the sending volume using this copy.

  4. Repeat as Necessary: Continue this iterative process to continuously refine and improve your email copy.

By following this structured approach, you can ensure that your cold email campaigns are optimized for maximum effectiveness based on real data.

Clean HTML & Remove Attachments

Ensuring your cold email copy is free of HTML code is crucial, as hidden HTML can negatively impact your results. Often, HTML can be inadvertently included when copying and pasting text from other tools or software.

To clean out any hidden HTML, simply navigate to your campaign settings and enable "Send as Plain Text"

Additionally, avoid including attachments in your cold emails. Attachments can trigger spam filters and reduce deliverability.

Instead, use links to direct recipients to any additional information or documents they may need.

By maintaining clean HTML and avoiding attachments, you can improve your email deliverability and overall campaign performance.

Open Tracking (and Turning It Off)

Tracking open rates can provide valuable insights into the overall health of your cold email outreach. However, there are trade-offs to consider:

  1. Tracking Pixel Impact: Open rates are tracked via a tracking pixel, which is technically an attachment. As previously discussed, any attachment can negatively impact deliverability.

  2. Misleading Metrics: Privacy features of email service providers and bots that pre-scan emails can cause open rates to be inaccurate. This can result in misleading data, giving a false impression of your campaign's performance.

Once you are satisfied with the health of your sending accounts, you can potentially enhance your results by disabling open tracking.

This can be done with a simple click in the campaign’s settings tab, improving deliverability by eliminating the tracking pixel.



Additional Optimization

Disabling Bad Performers

Even if your overall cold email statistics are looking good, you can often achieve significantly better results by disabling underperforming campaigns. Here's how to optimize this:

  1. Identify Poor Performers: Analyze your campaigns to find those with below-average results.

  2. Troubleshoot or Cut: While you can troubleshoot to understand the reasons for poor performance, often it's more effective to simply cut the worst performers.

  3. Reallocate Resources: Redirect the sending volume from these poor performers to better-performing campaigns. This will generate more positive interactions, enhancing your sending reputation and creating a positive snowball effect.

Daily Health Checkups

Consistent monitoring of your campaigns is crucial to maintaining a high sending reputation. Here’s how to stay on top of your cold outreach health:

  1. Monitor Key Metrics: Keep an eye on open rates, reply rates, and bounce rates. Low open rates, low reply rates, and a high number of bounces are signs of bad deliverability.

  2. Adjust Accordingly: If you notice signs of poor deliverability, immediately stop or significantly reduce your cold outreach.

  3. Daily Review: Dedicate 30 minutes each day to review your campaigns. This proactive approach will help you quickly identify and address any issues, preventing long-term damage to your domains and accounts.

By routinely checking your campaigns and cutting underperforming ones, you can maintain a strong sending reputation and continually improve your cold email results.

When to Pause Cold Outreach Completely

If you notice that your open rates or warm-up health score are suspiciously low or continuing to decline, it might be time to pause your cold outreach entirely. Here's how to approach this:

  1. Complete Pause: Stop sending cold emails entirely (send 0 cold emails per day) and allow the warm-up system to run independently for a week or two, similar to how you would handle new accounts.

  2. Evaluate Improvement: After the pause, resume with a low sending volume to see if your metrics have improved. It may take 1-2 weeks of warm-up to rehabilitate a damaged sending reputation.

  3. Ongoing Strategy: This method can be applied at any time. If you suspect that your emails are being marked as spam, halt all cold outreach and let the warm-up system run solo. Once your reputation improves, gradually reintroduce cold emails at lower volumes.

Main Metrics/KPIs for Cold Email to Optimize For

When optimizing your cold email campaigns, focusing on key performance indicators (KPIs) is crucial. Here are the main metrics to track, in order of importance:

  1. Revenue: The ultimate measure of success is the revenue generated from your cold email campaigns. This metric directly reflects the financial impact of your efforts.

  2. Positive Replies: The number of positive replies indicates how many recipients are interested in your offer or proposal. It’s a strong indicator of campaign effectiveness.

  3. Positive Reply Rate: This is the percentage of total emails sent that receive a positive reply. It helps measure the efficiency of your email copy and targeting.

  4. Bounce Rate: The percentage of emails that could not be delivered. A high bounce rate can damage your sending reputation and indicates poor lead list quality.

  5. Reply Rate: The overall percentage of emails that receive any reply, whether positive or negative. It provides insight into the engagement level of your audience.

  6. Open Rates: The percentage of recipients who open your email. While it’s a good health indicator, it can be misleading due to privacy features and pre-scanning by bots.

Revenue

Revenue is the most critical metric for any cold email campaign. If your campaign generates revenue, it remains valuable regardless of other metrics, such as open rates.

How to Improve Revenue:

  1. Better Targeting: Ensure your emails reach the right audience. Refining your targeting strategy can significantly increase the relevance and effectiveness of your campaigns.

  2. Raising Prices: Evaluate your pricing strategy. Sometimes, increasing prices can lead to higher revenue without necessarily increasing sales volume.

  3. Increasing Conversion Rate: Optimize your email content, call-to-action, and landing pages to convert more recipients into paying customers.

Positive Replies

A positive reply is a lead that responds favorably to your email, whether it’s scheduling a meeting or simply expressing interest. This is the second most important metric, and optimizing for it is crucial to your campaign's success.

How to Improve Positive Replies:

  1. Better Targeting: Ensure your emails are reaching the right audience. Refine your segmentation and targeting to align with your ideal customer profile.

  2. Better Copy: Enhance your email content to be compelling, clear, and persuasive. Focus on strong subject lines, engaging openings, and a clear call-to-action.

  3. Better Personalization: Tailor your emails to each recipient. Use their name, reference specific details about their business, and address their unique pain points.

  4. Improving Leads to Meetings Ratio: Streamline the process of converting positive replies into scheduled meetings. This could involve simplifying the booking process, using automated scheduling tools, and following up promptly.

Positive Reply Rate


The positive reply rate provides a clear view of how effectively your campaigns are performing. Optimizing this rate should be a key focus.

How to Improve Positive Reply Rate:

  1. Better Targeting: Ensure your emails reach the most relevant audience. Refine your targeting criteria to better match your ideal customer profile.

  2. Better Copy: Craft compelling, clear, and persuasive email content. Focus on creating strong subject lines, engaging openings, and compelling calls-to-action.

  3. Better Personalization: Customize your emails to each recipient. Use their name, reference specific details about their business, and address their unique challenges and needs.

Bounce Rate

Bounce rate represents the percentage of emails that fail to reach their intended recipients because the addresses don't exist. Aim to keep your bounce rate below 2%.

How to Improve Bounce Rate:

  1. Change Lead Source: Ensure you are sourcing your leads from reputable providers. Poor-quality leads often result in higher bounce rates.

  2. Use Email Cleaning/Verification: Utilize tools and services that verify and clean your email lists before sending. This process removes invalid addresses, significantly reducing your bounce rate.

Reply Rate

Reply rate measures the percentage of recipients who respond to your email, including both positive and negative replies. While this is considered a vanity metric and isn't directly correlated with success, it still provides insight into overall engagement.

How to Improve Reply Rate:

  1. Better Targeting: Ensure your emails are reaching the right audience by refining your segmentation.

  2. Better Copy: Enhance your email content to be more engaging and relevant to the recipient's needs.

Open Rates

Open rates indicate how many recipients opened your email and serve as a symptomatic KPI to gauge if your campaigns are being delivered effectively.

How to Improve Open Rates:

  1. Ensure Correct Tech Setup: Verify that your SPF, DKIM, and DMARC settings are properly configured.

  2. Warm Up Domains Longer: Spend more time warming up your domains before launching full-scale campaigns.

  3. Pause Low Open Rate Campaigns: Temporarily halt campaigns with low open rates to prevent damaging your sending reputation. Assess and adjust these campaigns before resuming.

Buy Backup Domains and Create Backup Email Accounts

Once your pipl.ai account is up and running, it's wise to purchase backup domains and create backup email accounts, then put them through the warmup process. This strategy allows you to swiftly switch to fresh, warmed-up accounts if any issues arise with your active ones.

Benefits of Having Backup Domains and Email Accounts:

  1. Maintain Deliverability: If your deliverability drops, you can pause active accounts and replace them with backup ones until the warmup process restores their reputation.

  2. Quick Recovery: In case your accounts get burned, you can switch them out immediately, minimizing downtime.

  3. Seamless Scaling: If you need to scale up your operations, having pre-warmed backup accounts allows you to expand without waiting for new accounts to warm up.

Scaling Up Once You Start Getting Positive Replies

Cold emailing can be scaled up with minimal costs and risks. Once your campaigns are delivering positive replies, the next logical step is to increase your volume by acquiring new domains and email accounts.

Steps to Scale Up:

  1. Prepare Backup Accounts: As previously mentioned, have backup domains and email accounts warmed up and ready to deploy.

  2. Increase Volume: Gradually increase the number of emails you send as your positive reply rate improves.

  3. Monitor Performance: Continuously track the performance of your new accounts to ensure they maintain high deliverability and engagement.

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