How are email bounce rates calculated and what is considered a good bounce rate?
Michael Ko
Co-founder & CEO, Suped
Published 9 Jun 2025
Updated 15 Aug 2025
7 min read
Email bounce rates are a critical metric for anyone sending emails, whether for marketing, transactional purposes, or general communication. A high bounce rate indicates underlying issues that can severely impact your sender reputation and deliverability. Understanding how this rate is calculated and what constitutes an acceptable figure is fundamental to maintaining a healthy email program.
When an email bounces, it means it couldn't be delivered to the recipient's inbox. This can happen for various reasons, from temporary server issues to invalid email addresses. Monitoring your bounce rate helps you identify problems early, allowing you to take corrective action before your deliverability suffers significantly.
Understanding email bounce rate calculations
Calculating your email bounce rate is straightforward. It's expressed as a percentage, representing the proportion of your sent emails that did not reach their intended recipients. The standard formula involves dividing the total number of bounced emails by the total number of emails sent, then multiplying by 100 to get a percentage.
Email bounce rate formula
Bounce Rate = (Total Bounced Emails / Total Emails Sent) x 100
For example, if you send 10,000 emails and 200 of them bounce, your bounce rate would be (200 / 10,000) x 100 = 2%. This simple calculation provides a clear snapshot of your email list's health. It's a fundamental metric for evaluating the effectiveness of your email campaigns and the quality of your recipient list.
While the formula is simple, the specifics of what counts as a "bounced email" can sometimes lead to confusion, especially when comparing different email service providers (ESPs) or industry benchmarks. Some providers might only count hard bounces, while others include both hard and soft bounces in their reported bounce rates. This distinction is crucial for accurate interpretation of the data.
Metric
Formula Example
Resulting Bounce Rate
Basic Calculation
(200 bounces / 10,000 sent) x 100
2%
Considering only hard bounces
(50 hard bounces / 10,000 sent) x 100
0.5%
Including hard and soft bounces
(50 hard + 150 soft bounces / 10,000 sent) x 100
2%
Hard bounces versus soft bounces
Email bounces fall into two main categories: hard bounces and soft bounces. Understanding the difference between hard and soft email bounces is crucial for effective email list management and maintaining a good sender reputation.
A hard bounce indicates a permanent delivery failure. This usually happens because the email address is invalid, non-existent, or has been permanently disabled. When you receive a hard bounce, that email address should be immediately removed from your mailing list to prevent future delivery attempts and protect your sender reputation. Continuously sending to addresses that generate hard bounces can lead to your domain being placed on an email blocklist.
Soft bounces, on the other hand, are temporary delivery failures. These can occur due to a full inbox, server issues, the recipient's mail server being temporarily down, or the message size being too large. Unlike hard bounces, soft bounces don't always require immediate removal of the address, as the issue might resolve itself. Most ESPs will retry sending soft-bounced emails for a certain period before giving up.
Hard bounces
Definition: Permanent delivery failures, often due to invalid or non-existent email addresses.
Action required: Immediately remove the email address from your list.
Example reasons: Full mailbox, server temporarily unavailable, message too large.
Defining a good bounce rate
What constitutes a "good" email bounce rate is a common question, and the answer can vary depending on industry, list quality, and sending practices. However, general benchmarks exist that can guide your expectations. For most email campaigns, a bounce rate of 2% or less is generally considered healthy. Some experts even suggest aiming for less than 1% for optimal deliverability.
It's important to differentiate between hard and soft bounce rates when assessing what's acceptable. For hard bounces, a rate consistently above 0.5% to 1% signals a problem with your list hygiene or acquisition methods. This needs immediate attention, as Internet Service Providers (ISPs) view high hard bounce rates as a strong indicator of spamming behavior.
Soft bounce rates can be slightly higher, but a rate exceeding 2-5% could still point to issues, such as engagement problems or temporary blockages by receiving servers. While individual soft bounces are usually temporary, a pattern of high soft bounces for certain domains or segments of your list warrants investigation.
Email bounce rate benchmarks
Overall bounce rate: Aim for 2% or lower.
Hard bounce rate: Keep this below 0.5-1%.
Soft bounce rate: Ideally below 2-3%, but up to 5% might be acceptable depending on specific circumstances.
Impact and reduction strategies
High bounce rates, particularly hard bounces, significantly harm your sender reputation. ISPs and email providers track your bounce rates as a key indicator of your sending practices. A poor reputation can lead to your emails being directed to the spam folder, or even outright rejected, regardless of the quality of your content. This is why it's crucial to minimize bounces to improve email deliverability.
To reduce bounce rates, focus on maintaining a clean and engaged email list. This means regularly removing invalid or inactive addresses. Employing a double opt-in process for new subscribers can prevent invalid sign-ups from the start, as it verifies that the email address is legitimate and the subscriber genuinely wants to receive your communications. Regularly scrubbing your list is a proactive step that will yield significant benefits.
Beyond list hygiene, ensure your email content adheres to best practices, avoiding spammy triggers or deceptive subject lines. A well-segmented and personalized approach can also improve engagement and reduce the likelihood of soft bounces caused by recipient disinterest. Continuous monitoring of your bounce rates through your ESP or Google Postmaster Tools (or other postmaster tools from providers like Yahoo) is key to early detection and resolution of problems.
Regularly clean your list: Remove hard bounces immediately and consider re-engaging or removing inactive subscribers.
Use double opt-in: Verify email addresses at signup to ensure accuracy and subscriber intent.
Segment your audience: Send relevant content to specific groups to boost engagement and reduce soft bounces.
Monitor blocklists (blacklists): Check if your domain or IP is listed, as this can lead to bounces. Use a blocklist checker.
Review email content: Avoid spam trigger words, excessive images, or poor formatting that might trigger filters.
Views from the trenches
Best practices
Implement a consistent list hygiene routine to remove invalid email addresses promptly.
Use a double opt-in process for all new subscribers to verify their email addresses.
Regularly monitor your bounce rates, distinguishing between hard and soft bounces.
Segment your email lists to send more relevant content, improving engagement and reducing temporary blocks.
Common pitfalls
Failing to differentiate between hard and soft bounces, treating them all the same.
Ignoring industry benchmarks because they don't align with your internal metrics.
Sending to old, unengaged lists without proper re-engagement or cleaning, leading to high bounces.
Assuming a delivered email means it reached the inbox; it might still be spam-filtered.
Expert tips
Look beyond just the overall bounce rate. Analyze hard and soft bounces separately for clearer insights.
Be aware that different email service providers (ESPs) might calculate and report bounce rates differently.
Understand that industry benchmarks are generalized and your specific context might dictate a slightly different 'good' rate.
Focus on the actual deliverability and inbox placement rates, not just bounces, for a complete picture.
Marketer view
Marketer from Email Geeks says they presume benchmarks refer to hard bounces, but many reports don't clarify this distinction. They found that Constant Contact's numbers, which appear to combine hard and soft bounces, track closer to their own experience with clients.
2020-04-15 - Email Geeks
Expert view
Expert from Email Geeks says that industry benchmarks are often not serious calculations and can be considered marketing fluff. Real-world practices for list hygiene and sending vary widely.
2020-04-15 - Email Geeks
Final thoughts on email bounces
Email bounce rates are a vital indicator of your email program's health and directly influence your deliverability and sender reputation. By understanding how bounce rates are calculated and the distinctions between hard and soft bounces, you can proactively manage your email lists.
While industry benchmarks offer a helpful guide, the most effective strategy involves consistently monitoring your own performance, maintaining rigorous list hygiene, and adapting your sending practices to keep your bounce rate low. This diligence ensures your messages reliably reach the inbox and contribute to successful communication.
Yahoo) is key to early detection and resolution of problems.
