Reduce your email bounce rate

A bounce is a message the receiving side refused to deliver. Bounces matter because mailbox providers treat a sender who keeps mailing addresses that do not exist as careless, or as a spammer, and start filtering their mail. You lower your bounce rate by keeping bad addresses off your list in the first place and by acting on every bounce you do get.

Hard and soft bounces

• Hard bounce: a permanent failure, such as a mailbox or domain that does not exist. Retrying will not help; the address must be removed.
• Soft bounce: a temporary failure, such as a full mailbox, a server that is down, or a message that was too large. It may succeed later, but an address that soft-bounces again and again should be treated like a hard bounce.

Your sending platform reports the bounce code for each failure. Most platforms suppress hard bounces automatically; check that yours does.

Why bounces hurt

Mailbox providers look at how senders behave. Many bounces signal a list that was not collected or maintained carefully, so more of your mail may go to spam folders or be refused, including mail to valid addresses. The large providers publish what they expect from senders; read the guidelines of the providers your audience uses, such as Google's email sender guidelines.

Checklist for every campaign

1. Verify at capture. Check addresses on sign-up and lead forms so typos are fixed while the person is still there (sign-up form guide).
2. Use confirmation emails where it fits your product, so only people who control the mailbox are added.
3. Verify before large sends, especially for segments you have not mailed recently (list cleaning).
4. Remove undeliverable and risky addresses with the action remove; send carefully to catch-all segments.
5. Suppress hard bounces at once, and soft bounces that repeat.
6. Authenticate your domain with SPF, DKIM and DMARC, so receivers can tell your mail from forgeries.
7. Ramp up new domains and IPs gradually rather than starting with your whole list.
8. Watch the numbers per source. If one form, partner or import produces most bounces, fix it at the source.

What verification does and does not prevent

Verification removes addresses that cannot receive mail today, which prevents most hard bounces. It cannot prevent bounces caused by your own reputation, content filtering or a mailbox that closes after the check, and it cannot confirm mailboxes on catch-all domains. That is why monitoring bounces stays part of the routine.

Try it

Check a single address with the free email checker or clean a whole list with bulk verification.

How we wrote this: drafted by the email-validation.org team with the help of AI writing tools, from our product documentation and the sources linked in the text.