Email bounce rate
What is the email bounce rate?
An email bounce occurs when an email cannot be delivered to a recipient’s inbox. The email bounce rate refers to the percentage of emails that fail to reach recipients out of the total number of emails sent.
How do you calculate the email bounce rate?
The email bounce rate is a key metric that helps evaluate your sender reputation and effectiveness of your email sending practices. The rate is calculated using the following formula:
Bounce rate (%) = (Number of bounced emails ÷ Total emails sent) × 100 |
For example:
If you send 1,000 emails and 50 of them bounce, then the email bounce rate is 5%.
Bounce rate = (50 ÷ 1000) × 100 = 5%
Why do email bounce rates matter?
Email bounce rates are more than just a delivery metric, they directly impact your overall email performance and sender reputation. Focusing on the bounce rate can help:
Protect your sender reputation: High bounce rates signal poor sending practices to mailbox providers, which can damage your sender reputation over time.
Improve email deliverability: Lower bounce rates increase the chances of your emails reaching the inbox instead of being blocked or filtered into spam.
Send emails to the right email address: Bounce rates act as a health check for your email list, helping you identify outdated, invalid, or low-quality email addresses.
Prevent blacklisting risks: Continuously sending emails to invalid addresses can lead to your domain or IP being blacklisted.
Build trust with users: For time-sensitive transactional emails like password resets or OTPs, high bounce rates can directly impact user experience and trust.
Common reasons for high bounce rates
A high bounce rate can happen due to several factors:
Typos in email addresses: Simple spelling errors during signup can result in non-existent email addresses that bounce immediately.
Inactive or abandoned email accounts: Email accounts that are no longer in use may be deactivated by providers, causing hard bounces when you send emails.
Sending without proper authentication: Without authentication protocols (SPF, DKIM, DMARC) in place, receiving servers may reject your emails due to lack of trust or security validation.
Blocked or blacklisted sender IP/domain: If your sending domain or IP is flagged for spam-like behavior, mailbox providers may block your emails altogether.
Sudden spikes in email volume: Sending a large volumes of emails unexpectedly can trigger spam filters and lead to higher bounce rates.
Strategies for reducing your email bounce rate
Here are some practical ways to keep your bounce rate low.
Validate emails at signup
Use a double opt-in method to ensure that users confirm their email address during signup on your app or website. This helps validate the accuracy of the email address and reduces the chances of fake, invalid, or mistyped entries entering your list.
Maintain suppression list
Maintain a list of invalid email addresses, hard bounces, and inactive subscribers, and exclude them from future sends. This prevents repeated delivery failures and protects your sender reputation over time.
Implement email authentication
Set up authentication protocols such as SPF, DKIM, and DMARC. This improves trust with receiving servers and reduces the likelihood of your emails being rejected or flagged.
Monitor bounce metrics
Choose a platform that helps you track bounce trends and identify issues early. Regular tracking and monitoring allows you to take corrective action before bounce rates impact your email deliverability.
Warm up your sending domain/IP
If your business sends a large volume of emails, gradually increase your sending volume over time. This process, known as email warm-up, helps build a strong sender reputation and reduces the risk of being flagged by mailbox providers.