How to Reduce Your Email Bounce Rate
A high bounce rate is one of the clearest signals to inbox providers that you don’t know who you’re emailing — and it drags down the deliverability of every message you send. Keeping bounces low is one of the highest-leverage things you can do for cold email.
Here’s what bounce rate is, what’s healthy, and how to bring it down.
What is email bounce rate?
Bounce rate is the percentage of emails that couldn’t be delivered and were returned by the receiving server: (bounced emails ÷ emails sent) × 100. A bounce means the message never reached the inbox at all.
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Hard bounces vs. soft bounces
- Hard bounce: a permanent failure — the address doesn’t exist, the domain is invalid, or the server permanently rejected it. These are the dangerous ones; remove them immediately.
- Soft bounce: a temporary failure — a full mailbox, a server that’s down, or a message too large. These often resolve, but repeated soft bounces should be pruned too.
What’s a good email bounce rate?
For cold outreach, keep your bounce rate under about 2–3%. Under 2% is healthy; above 5% is a serious problem that will hurt deliverability and may get your sending paused. The lower, the better.
Why bounces hurt so much
Every hard bounce tells Gmail and Outlook you’re emailing addresses you didn’t verify — classic spammer behavior. A rising bounce rate damages your sender reputation, which lands even your valid emails in spam. Bounces don’t just waste a send; they make every other send worse. See the deliverability guide for the full picture.
How to reduce your bounce rate
- Verify every address before you send. This is the single biggest lever — verification removes invalid addresses before they bounce. Outboundry’s Email Finder & Verification does it at the point of use.
- Don’t buy or scrape lists; bought data is full of dead addresses and traps.
- Remove catch-all and risky addresses, or send to them cautiously.
- Keep lists fresh — B2B data decays fast as people change jobs, so re-verify older lists.
- Authenticate and warm up; some “bounces” are rejections from poor reputation, fixed by SPF/DKIM/DMARC and warmup.
- Prune hard bounces immediately and suppress them from future sends.
Monitor your bounce rate
Watch bounce rate per campaign and over time. A sudden spike usually means a bad list segment or a reputation problem — catch it early, before it spreads to the rest of your sending.
Frequently asked questions
What is a good email bounce rate?
Under about 2–3% for cold outreach; under 2% is healthy, and above 5% needs immediate attention.
What’s the difference between a hard and soft bounce?
Hard bounces are permanent (bad address); soft bounces are temporary (full mailbox, server down). Remove hard bounces right away.
How do I lower my bounce rate?
Verify addresses before sending — the biggest lever — and avoid bought lists, keep data fresh, and authenticate your domain.
Do bounces affect deliverability?
Yes, significantly. High bounce rates damage sender reputation and push your other emails toward spam.
Keep bounces low automatically
Outboundry keeps bounces low automatically — find and verify contacts in one step against a 700M+ database before they ever enter a campaign. Start your free trial.