How to reduce your email bounce rate

Hard bounces vs soft bounces

A hard bounce is permanent: the address doesn't exist or the domain can't receive mail. A soft bounce is temporary: a full mailbox, a server hiccup, or a message that's too large. Hard bounces are the ones that damage your reputation, and they're almost entirely preventable with verification.

What causes high bounce rates

• Unverified sign-ups — typos and fake addresses entering your list at capture.
• Old, un-maintained lists — addresses that were valid once but have since been abandoned.
• Purchased or scraped lists — almost always full of dead addresses and spam traps.
• Missing authentication — no SPF, DKIM, or DMARC, so providers distrust your mail.

How to fix it

• Verify at signup so invalid addresses never enter your list.
• Verify your existing list before big sends, and re-verify every few months.
• Use double opt-in for new subscribers to confirm intent and accuracy.
• Set up SPF, DKIM, and DMARC on your sending domain.
• Never buy or scrape lists — the short-term reach isn't worth the reputation damage.
• Warm new sending domains and IPs gradually instead of blasting from day one.

What's a good bounce rate?

Aim to keep hard bounces under about 2% — under 1% is better. If you're above that, verification is usually the fastest lever: it removes the dead addresses that generate hard bounces before they ever hurt you.