Understanding the Difference Between Hard Bounces and Soft Bounces

Avatar for Sean Heilweil Sean Heilweil
Avatar for Sean Heilweil Sean Heilweil

December 10, 2021

3 min read

Understanding the Difference Between Hard Bounces and Soft Bounces

Getting started in email marketing can feel like learning how to speak a new language. At some point, the industry jargon starts sounding like R2D2’s beeps. Terms like ESP, CTR, CTA, CAN-SPAM, HTML, SPF (not the sunscreen), DKIM, SMTP, Soft Bounce, Hard Bounce, and numerous others, can get overwhelming.

At times, the jargon barrier feels like running into a brick wall of marketing. Fortunately, you don’t need to take a hard bounce off of the brick wall to understand the difference between hard bounces and soft bounces, and implement email marketing best practices.

We’re here to help.

The Difference Between Hard Bounces and Soft Bounces

Hard and soft bounces have to do with email deliverability. A bounce means that an email can’t be delivered. If an email is getting bounced, that’s not good. Bounces waste money, time, and hurt your sender score. The industry standard for bounce rates shouldn’t be higher than 2%. Here’s how to calculate your bounce rate:

If you’re experiencing a bounce rate higher than 2%, your sender score will be damaged, leading your email campaigns straight into the SPAM and promotions folders. Let’s take a deeper dive into the two main types of bounces so we can gain a better understanding of them, to prevent them from happening.

What is a hard bounce?

A hard bounce is permanent. It’s a hard “No”. It means that no matter how hard you try, the email will not deliver. This can happen for several reasons:

  • The email address was rejected by the mail server because it does not exist.
  • The email address domain does not exist or is not valid.
    • This can happen if a company changes domains, or closes.
  • The email address does not pass syntax validations.
    • Typos in the email address.

As hard as it might be to let go of precious emails that you’ve collected over several years of hard-work, sweat and tears, if an email is a hard bounce, you need to remove it from your mailing list. You need to let it go.

If you have thousands of hard bounce emails, you might be “frozen” in fear at the thought of manually unsubscribing them. Luckily, there are several email verification services that will do the dirty work for you, automating the email cleanup process.

What is a soft bounce?

A soft bounce is temporary. It’s an email that can’t be delivered ~right now~. In other words, the email made it to the doorstep, but not inside the house. Or, as Megan Thee Stallion would say, if she was an email address, “I can’t talk right now, I’m doing hot email stuff”. This can happen for a variety of reasons, such as:

  • Their inbox is full.
  • Too many people are marking your email as SPAM.
  • An unresponsive email server.
  • The email account was suspended.
  • You’ve been blacklisted.

Oftentimes, soft bounces will resolve on their own. However, you should keep track of them because you don’t want them causing permanent issues.

It’s a good idea to reach out to your Email Service Provider, aka ESP (more jargon), about how they handle soft bounces. You will want to know if they retry soft bounces, for how long they retry them, and what they do if the email continues to be undeliverable. Keep in mind that soft bounces are still a part of your bounce rate.

How to improve your bounce rate?

The best way to improve your bounce rate is to implement some email marketing best practices into your workflow. Here are some quick tips on improving your bounce rate:

  • Maintain good list hygiene
    • Email lists naturally decay at about 2% per month. Over the course of the year, that’s over 20% of your email list that becomes undeliverable. This means that if you’re not cleaning your list on a regular basis, your bounce rate will be over the industry standard of 2%. The best email verification platforms will guarantees about their quality of service.
  • Track your emails
    • It’s a good idea to keep track of your email deliverability rates, as well as other key metrics. As mentioned above, having a knowledge base of how your ESP approaches soft bounces will help you track your deliverability and bounce rates. When you’re regularly monitoring your email lists and campaigns, you’ll be able to spot potential issues before they become a damaging problem.
  • Use a double opt-in
    • If you send a confirmation email when users subscribe, it helps filter out spammers and bad email recipients. This way, real subscribers double opt-in, and spammers are left in the dust. Stopping bad emails before they get into your list is a great preventative measure at protecting your deliverability rates.


If you’ve skipped straight to the summary, I am going to reward you with a tl;dr (too long; didn’t read…sorry about the jargon). Here it is:

Tl;dr: Hard bounce = permanent. Soft bounce = temporary. Both bounces can hurt your sender score, so you should clean your email list.

Got it? May your bounce rates be low, your email lists be clean, and the odds ever in your favor. Good luck, my email marketing friend.

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