Glossary Term
Bounce Rate
The percentage of sent emails that fail to deliver and are returned by the receiving server.
What is Bounce Rate?
Bounce rate measures what percentage of your emails fail to deliver. It's calculated as: (Bounced Emails / Total Sent) x 100.
Bounces are categorized as:
- Hard bounces: Permanent failures (invalid address, domain doesn't exist)
- Soft bounces: Temporary failures (mailbox full, server temporarily unavailable)
Acceptable bounce rates:
- Under 2%: Excellent
- 2-3%: Acceptable
- 3-5%: Warning - investigate
- Over 5%: Critical - stop sending
High bounce rates signal to email providers that you're sending to bad data - a hallmark of spammers. This damages your sender reputation and can lead to blacklisting.
Why It Matters
- 1Major signal of list quality to email providers
- 2High bounces damage sender reputation quickly
- 3Over 5% can trigger immediate blacklisting
- 4Indicates problems with your email verification process
How to Measure
Track bounces as a percentage of total sends. Monitor for sudden increases that might indicate list problems.
Related Tools
Related Guides
Related Terms
Hard Bounce
A permanent email delivery failure, typically because the email address or domain doesn't exist.
Soft Bounce
A temporary email delivery failure that may resolve itself, such as a full mailbox or server issue.
Email Verification
The process of confirming that an email address is valid, deliverable, and belongs to a real person.
Sender Reputation
A score assigned to your email-sending identity based on your historical sending behavior and recipient engagement.
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