# Email Bounce Rate: What It Is and How to Keep It Low

> A plain explanation of bounce rate for people sending cold outreach, with a worked example, the mistakes that push it up, and what to do before your next send.

Email bounce rate is the percentage of emails you sent that were returned as undeliverable instead of reaching an inbox. You calculate it by dividing the number of bounced emails by the number of emails sent, then multiplying by 100.

## Hard bounces and soft bounces

Not every bounce means the same thing, and the difference changes what you should do.

- **Hard bounce:** a permanent failure. The address does not exist, the domain is gone, or the receiving server refuses it outright. Remove these addresses and never send to them again.
- **Soft bounce:** a temporary failure. The mailbox is full, the server is busy, or the message was too large. These can succeed later, but an address that soft bounces again and again should be treated like a hard bounce.

When people talk about a bounce rate problem in outreach, they usually mean hard bounces, because those come from bad data.

## Why it matters when you do outreach

Mailbox providers watch how your sending behaves. Sending to lots of addresses that do not exist looks like what spammers do: they buy or guess lists and blast them. A high bounce rate tells receiving servers that you do not know who you are writing to.

That damages your [sender reputation](https://getclient.pro/learn/sender-reputation), and reputation follows you. Once it slips, even your emails to real, valid people are more likely to land in spam. So a bad list does not just waste those bounced sends. It drags down the ones that should have worked.

There is a practical cost too. Gmail, Outlook and most [SMTP](https://getclient.pro/learn/smtp) providers can limit or suspend accounts that bounce heavily. If you send from your main business mailbox, that is a real risk to your day-to-day email.

A common rule of thumb in cold email is to keep hard bounces under about 2 percent, and to stop and investigate well before 5 percent. These are working guidelines, not official limits, and every provider sets its own thresholds.

## A worked example

Say you run a small web design studio and send a first step to 400 local businesses.

- 400 emails sent
- 22 hard bounces (addresses that do not exist)
- 6 soft bounces (full mailboxes, temporary errors)

Total bounce rate: 28 / 400 = 7 percent. Hard bounce rate: 22 / 400 = 5.5 percent.

That is too high. If you also have follow-up steps queued, such as a [drip campaign](https://getclient.pro/learn/drip-campaign) with three more emails, those steps will try the same bad addresses again unless they are removed. The right move is to pause, remove the 22 hard bounces, check where the list came from, and verify the rest before continuing.

Now imagine the same 400 contacts verified first. Verification flags 30 as invalid and 15 as risky. You drop the invalid ones, hold the risky ones back, and send to 355. If 3 bounce, your rate is under 1 percent, and you protected the account you send from.

## Common mistakes that push bounce rate up

**Sending to unverified lists.** Addresses go stale as people change jobs and businesses close. A list that was fine six months ago may not be today.

**Guessing addresses.** Writing to firstname@company.com because it seems likely is a quick way to collect hard bounces.

**Buying lists.** You cannot know how old or how clean they are, and there are often legal questions as well. See [GDPR for outreach](https://getclient.pro/learn/gdpr-for-outreach) and check the rules that apply where you and your recipients are.

**Sending a big batch from a new account.** A fresh mailbox has no track record, so a burst of bounces hits harder. Start small and build up.

**Ignoring bounces between steps.** If your follow-ups keep firing at addresses that already bounced, you repeat the damage with every step.

**Counting catch-all addresses as safe.** Some domains accept mail for any address at the server level and bounce it later. Verification tools often mark these as risky. Treat them with care rather than as confirmed.

## What to do next

1. **Verify before every campaign**, especially for older lists or imports. It costs far less than a damaged sender reputation.
2. **Remove hard bounces immediately** and keep them off future lists.
3. **Send risky addresses separately** in small batches, or skip them, so they cannot drag down your main send.
4. **Use fresh data.** Pulling leads close to the time you send means fewer stale addresses. Defining tight criteria with [firmographics](https://getclient.pro/learn/firmographics) also helps you avoid junk entries.
5. **Watch the first step closely.** Check bounce numbers after the first few dozen sends, not after the whole list is done.
6. **Spread sending across days** with sensible daily limits per mailbox rather than one large blast.

## Where GetClient fits

Campaign analytics show how each campaign is performing, and send-day limits by weekday help you pace a new account. New accounts start with 100 free credits; see [plans and credits](https://getclient.pro/pricing) for the rest.

Whatever tool you use, the habit is the same: clean list in, bounces checked early, bad addresses removed for good.

## Frequently asked questions

### What is a good email bounce rate for cold email?

A widely used rule of thumb is to keep hard bounces under about 2 percent. If you go past that, pause, remove the bad addresses and verify the rest before sending more. It is a guideline, not an official limit.

### Do bounces count against me if the address was valid yesterday?

Yes. Receiving servers only see that you sent to an address that no longer accepts mail. That is why verifying close to the send date matters.

### Is an auto-reply or out-of-office message a bounce?

No. An auto-reply means the email was delivered to a working mailbox. Only delivery failure notices from the receiving server count as bounces.

### Should I retry soft bounces?

Retrying once or twice later is reasonable, since the problem may be temporary. If the same address keeps soft bouncing across sends, remove it as you would a hard bounce.

### Can I fix my sender reputation after a high bounce rate?

Usually you can recover by stopping sends to bad lists, verifying data, lowering volume for a while and sending only to real, relevant contacts. Recovery takes time, so prevention is much easier.

Source: https://getclient.pro/learn/email-bounce-rate