Bounce Rate (Email)

An email bounce occurs when your message cannot be delivered to the recipient’s email address. There are two types: a hard bounce means the email address is invalid, does not exist, or has permanently rejected messages — these addresses should be removed from your list immediately. A soft bounce is a temporary delivery failure (the inbox is full, the server is down) — these can be retried a few times before removal.

Why It Matters

A high bounce rate damages your sender reputation with internet service providers (ISPs), which leads to more of your emails landing in spam — even for valid addresses. Most email marketing platforms will automatically suppress addresses that hard-bounce, but if you are importing lists from other sources, you need to validate them before sending. Maintaining a bounce rate below 2% is the standard benchmark.

Causes of High Bounce Rates

The most common causes include: outdated lists with addresses that are no longer active, purchased or scraped lists (which are almost always problematic), typos in email addresses collected through forms, and role-based addresses (like info@ or admin@) that tend to have aggressive spam filtering. Regular list hygiene — removing addresses that have not engaged in 6–12 months — prevents bounce rates from climbing.

How to Fix It

Run your list through an email verification service before any large send. Set up double opt-in so only people who confirm their address are added to your list. Review your hard bounce addresses monthly and remove them. If your bounce rate spikes after a specific import or campaign, investigate that source and clean accordingly.