In today's competitive digital landscape, email marketing plays a vital role in engaging with your audience and driving business growth. However, ensuring that your emails reach the intended recipients is essential for a successful email marketing campaign. Bounced emails can be a significant obstacle to achieving high deliverability rates and can impact your sender reputation. In this comprehensive guide, we will explore the world of bounced emails in Klaviyo, a popular email marketing platform. We will delve into the causes of bounced emails, their impact on deliverability, and provide strategies to effectively manage them for optimal campaign performance.

Understanding Bounced Emails

email bounced

When an email fails to reach its intended recipient and is returned to the sender, it is known as a bounced email. Bounced emails can occur due to various reasons, such as invalid email addresses, full mailboxes, or server-related issues. Understanding the different types of bounced emails is crucial in identifying and resolving deliverability challenges.

  1. Hard Bounces: Hard bounces occur when an email cannot be delivered to a recipient due to a permanent error. The most common reasons for hard bounces include invalid or non-existent email addresses, domain name errors, or blocked email servers. Hard bounces should be removed from your email list immediately to maintain a healthy sender reputation.
  2. Soft Bounces: Soft bounces are temporary delivery failures that can be caused by reasons such as a recipient's mailbox being full, a server being temporarily unavailable, or a message being too large. Unlike hard bounces, soft bounces may still have a chance of successful delivery in the future. However, if soft bounces persist for an extended period, they should be treated as potential deliverability issues and addressed accordingly.

The Impact of Bounced Emails on Deliverability

bounced emails

Bounced emails can have a negative impact on your email deliverability and sender reputation. Internet service providers (ISPs) and email service providers (ESPs) use bounce rates as a measure of email quality and engagement. High bounce rates signal potential spam or poor list hygiene, which can result in your emails being marked as spam or blocked altogether. It is essential to actively manage bounced emails to maintain a positive sender reputation and ensure optimal deliverability for your campaigns.

Reducing Bounced Emails

bounced emails
  1. Maintain a Clean Email List: Regularly clean and update your email list to remove invalid or inactive email addresses. Use double opt-in processes to verify the accuracy of email addresses during the subscription process. Implementing proper list hygiene practices will significantly reduce the occurrence of hard bounces.
  2. Monitor and Analyze Bounce Rates: Track and analyze your bounce rates in Klaviyo's reporting and analytics features. Identify trends and patterns in bounce rates to pinpoint potential issues and take corrective actions promptly.
  3. Use Proper Email Validation Techniques: Implement email validation techniques to verify the accuracy and validity of email addresses before adding them to your list. This can include using third-party email validation services or implementing real-time validation during the subscription process.
  4. Implement Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting, and Conformance (DMARC): These email authentication protocols help verify the authenticity of your emails and protect against spoofing and phishing attempts. Implementing these protocols correctly can improve your email deliverability and reduce the chances of bounces.

Managing Bounced Emails in Klaviyo

  1. Review the Bounced Email Metrics in Klaviyo: Klaviyo provides detailed bounce reports and metrics that allow you to identify bounced emails easily. Access the bounce report section in Klaviyo's dashboard to gain insights into bounce types, rates, and specific email campaigns affected.
  2. Segment and Exclude Bounced Emails: Segment your email list based on bounce types and exclude hard bounces from future campaigns. This ensures that you are sending emails only to valid and engaged recipients, thereby improving deliverability rates and overall campaign performance.
  3. Identify and Resolve Common Issues: Analyze the reasons behind bounced emails and take appropriate actions to resolve any recurring issues. For example, if the bounce rate is high due to invalid email addresses, implement stricter validation processes during the subscription phase.
  4. Monitor Sender Reputation: Monitor your sender reputation by regularly checking blacklists and reputation monitoring services. If you notice any negative impact on your reputation, investigate the causes and address them promptly to maintain a positive sender image.
  5. Seek Support from Klaviyo's Customer Success Team: If you encounter persistent bounce-related issues or require further guidance, reach out to Klaviyo's customer success team. They can provide expert advice and assistance in optimizing your email deliverability and managing bounced emails effectively.

Commonly Asked Questions

Q1: How can I identify bounced emails in Klaviyo?

A: Klaviyo provides comprehensive bounce reports and metrics in its dashboard. You can access the bounce report section to identify and analyze bounced emails.

Q2: Should I remove soft bounces from my email list?

A: Soft bounces are temporary delivery failures and may still have a chance of successful delivery. However, if soft bounces persist for an extended period, it is recommended to investigate and take appropriate actions.

Q3: Can bounced emails affect my email deliverability?

A: Yes, high bounce rates can negatively impact your email deliverability and sender reputation. ISPs and ESPs consider bounce rates when determining email quality and engagement.

Q4: How frequently should I clean my email list?

A: It is advisable to clean your email list regularly to remove invalid or inactive email addresses. The frequency of list cleaning may vary depending on your email marketing practices and subscriber engagement rates.

Q5: What other factors can affect email deliverability?

A: Email deliverability can be influenced by various factors, including email content, engagement rates, spam filters, and sender authentication protocols. It is essential to implement best practices in all these areas to optimize deliverability.


Managing bounced emails is a critical aspect of maintaining high email deliverability rates and a positive sender reputation. By understanding the types of bounced emails, their impact on deliverability, and implementing effective strategies in Klaviyo, you can improve your email marketing campaigns' performance. Regularly monitor and analyze bounce rates, maintain a clean email list, and take appropriate actions to address bounce-related issues promptly. With these best practices, you can maximize the success of your email campaigns, enhance engagement with your audience, and achieve your marketing goals in Klaviyo.