This guide explains what email bounce rates are, why they matter, and how to reduce them to maintain strong deliverability and sender reputation.
What is an Email Bounce Rate?
Bounce rate measures how often your emails fail to be delivered.
A bounce occurs when:
An email is rejected by the recipient’s server
The email address is invalid or unreachable
There are two types of bounces:
Hard Bounce
Permanent failure (e.g., invalid or non-existent email)
These contacts should be removed immediately
Soft Bounce
Temporary failure (e.g., full inbox, server issue)
May resolve over time but should be monitored
Bounce rate is calculated as the number of bounced emails divided by the total emails sent.
Why Bounce Rates Matter
High bounce rates can negatively impact your deliverability and sender reputation.
If bounce rates increase:
Inbox providers may flag your emails as low quality
Your emails may start landing in spam
Future campaigns may be affected
Learn more: What is Sender Reputation and Why It Matters
Common Causes of High Bounce Rates
Sending to invalid or outdated email addresses
Poor list acquisition practices
Lack of list maintenance
Sending to unengaged or inactive users
How to Reduce Bounce Rates
1. Send Only to Verified, Opted-In Users
Always email users who have explicitly subscribed.
Avoid:
Purchased lists
Third-party data sources
Unverified contacts
Sending to unverified users increases the risk of invalid or low-quality email addresses.
2. Use Double Opt-In
Double opt-in requires users to confirm their subscription before being added to your list.
Benefits:
Ensures valid email addresses
Reduces fake or mistyped signups
Improves list quality
3. Clean Your Contact Lists Regularly
List cleaning helps remove:
Invalid email addresses
Inactive users
Low-quality contacts
This reduces bounce rates and improves overall engagement.
4. Remove or Suppress Soft Bounces
If an email address repeatedly soft bounces:
Exclude it from campaigns
Suppress it if the issue persists
Even temporary failures can harm your reputation if repeated frequently.
5. Be Careful with Rapid List Growth
Certain acquisition methods (like giveaways or contests) may introduce:
Low-quality or fake email addresses
Users who are not genuinely interested
To manage this:
Segment new subscribers
Monitor engagement before scaling sends
Clean lists more frequently
6. Focus on Engaged Audiences
Sending primarily to engaged users helps:
Reduce bounce risks
Improve deliverability signals
Maintain a strong sender reputation
Monitor and Act on Trends
Don’t just look at a single campaign—monitor bounce rates over time.
Take action if you notice:
Sudden spikes
Consistent increases
Declining engagement alongside bounces
Learn more: Email Deliverability FAQs
Key Takeaway
Bounce rates are a critical indicator of list quality and sending practices. By focusing on verified subscribers, maintaining clean lists, and monitoring performance, you can reduce bounces and protect your deliverability.