Home » Soft bounce vs Hard bounce email: what’s the difference and how to avoid them
SafetyMails discusses the differences between Soft bounce vs Hard bounce email

Soft bounce vs Hard bounce email: what’s the difference and how to avoid them

When evaluating soft bounce vs hard bounce email, would you be able to list the differences between them, their impacts and how to avoid each type?

Since you’re in the world of email marketing, understanding some concepts such as soft bounces, hard bounces and the difference between them, is very important for maintaining a good sending reputation with email service providers (ESPs) and ensuring that your messages reach their recipients correctly.

At this point, it’s not just a question of knowing that a bounce means that an email message has not been delivered. You have to dig deeper, separate the types of bounces and the specific reasons for each one.

In this post, we’ll explore this topic with you.

What are soft bounces?

Soft bounces happen when an email message is temporarily rejected by the receiving server.

Basically, the reasons that can lead to a soft bounce range from technical problems, such as connection failures, unavailable servers, configuration problems, unstable domains, to more behavioral problems, such as full inboxes, too many messages sent in one day/time, non-compliance with an anti-spam rule or even because your domain or IP address is blacklisted.

Therefore, soft bounces indicate transient, temporary problems, which is why most of the time they are resolved with new sending attempts.

But, of course, there are cases where just one new sending attempt is not enough. If the problem identified is technical or behavioral, it will be necessary to readjust the problem that was indicated before any new attempt.

What are hard bounces?

Hard bounces, on the other hand, are permanent email rejections.

These rejections occur when the email address is invalid, non-existent, has been deleted, the domain is incorrect, etc. The fact is that this type of error is immutable and permanent.

Therefore, unlike soft bounces, hard bounces are not resolved by subsequent attempts to send.

Someone might say: if it’s a typo, like changing the position of letters, just correct the address and send. We agree in part: if you’ve changed the email, it’s no longer the same address, is it?

But, yes, one way to solve some hard bounces is to modify the email, if the problem is syntax (use of an invalid character), name or domain with a typo.

Main differences between Soft bounce vs Hard bounce email

As you’ve already seen, the main difference between Soft bounce vs Hard bounce email lies precisely in the nature of the rejection.

Soft bounces are temporary, reversible problems and can be resolved with some effort.

On the other hand, hard bounces are permanent, unchangeable problems and require the removal of the email address from the contact list to avoid future problems.

But what kind of problems could a hard bounce cause?

The impact of hard bounces on email marketing

Both soft bounces and hard bounces can negatively affect your email marketing campaigns.

Specifically, in the case of hard bounces, rates of just 3% of invalid emails will negatively affect the sender’s reputation and lead to severe blocks, which affect the deliverability of future emails.

So, when the email provider identifies you as sending invalid emails, it can classify your behavior as spamming. This is because the provider relates your hard bounce rates to a specific behavior: a lack of concern for lead quality – just like a spammer.

Hard bounces cause a drop in reputation, as well as blocks, which are a soft bounce.

Therefore, hard bounces cause soft bounce blocks, preventing valid email addresses from being delivered!

As a result, fewer emails will be delivered, and the few that are delivered may be directed to the spam folder, damaging the relationship and email marketing conversions.

The impact of soft bounces on email marketing

As you’ve seen here, soft bounces can indicate temporary delivery problems that need to be monitored.

If some of these problems are not dealt with, such as authentication failures, they can become another type of soft bounce: blocks. If a block happens, it already means that you have suffered a drop in reputation

How to manage and mitigate Soft Bounces and Hard Bounces

Effective management of all bounces is essential to maintaining a high delivery rate.

That’s why you need to take specific measures for both types of bounce. This is because the soft bounce vs hard bounce email rivalry has only one loser: the sender.

To manage and mitigate soft bounces, you need to solve the problems associated with them. For example, in the case of authentication errors or failures, you need to review these settings.

If the problem is related to an anti-spam block, you need to identify the cause and fix it (change the sending volume, some content, remove a domain from a blacklist, etc).

In the case of hard bounces, you’ll need to remove the invalid addresses from your list immediately. Implementing a strategy of checking emails before sending them can help minimize bounces and keep your contact list clean and up-to-date.

Email verification

Another fundamental measure to prevent hard bounces from entering your contact lists is to take care of the quality criteria of the registration forms through which these email address records are collected. If you prevent these emails from being collected at source, the better for your email marketing and sales results.

SafetyMails offers specialized email verification services, capable of identifying and removing:

  • Invalid emails of any kind
  • Nonexistent
  • Syntax errors
  • Domain errors
  • Spam traps
  • Temporary emails
  • Junk emails

SafetyMails has an API for verifying emails in real time that can be installed on your landing page registration forms, apps, point-of-sale terminals, CRM systems and more.

Take the opportunity to try email validation for free.


Understanding the differences between soft bounces and hard bounces is essential for any successful email marketing strategy.

In conclusion, soft bounces represent temporary problems that can be resolved and hard bounces indicate permanent rejections that require immediate action, such as removing invalid addresses from the contact list.

Managing these bounces effectively not only improves email deliverability, but also protects the sender’s reputation by ensuring that their messages reach the intended recipients.


What is a soft bounce?

A soft bounce occurs when an email is temporarily rejected by the receiving server. The reasons can range from full inboxes, temporary server problems or even connection failures. Soft bounces are usually resolved with subsequent sending attempts, but require monitoring to ensure that the underlying problems are identified and corrected.

What is a hard bounce?

A hard bounce is a permanent rejection of an email, indicating that the email address is invalid, non-existent or has been deleted. Other reasons can include incorrect domains or typos. Unlike soft bounces, hard bounces are not resolved by new sending attempts and require the immediate removal of these addresses from the contact list to avoid future problems.

How do soft bounces and hard bounces affect the sender’s reputation?

Both soft and hard bounces can damage a sender’s reputation. Frequent soft bounces can indicate technical or behavioral problems that need to be corrected. Hard bounces, however, even in small percentages, can lead email providers to classify the sender as a spammer, resulting in blocks and lower deliverability of future emails.

What are the best practices for managing soft bounces?

To manage soft bounces, it is crucial to constantly monitor the mailing list and resolve the specific problems associated with each temporary rejection. This can include correcting authentication failures, adjusting sending volumes or resolving blacklist issues. New sending attempts should be made after these problems have been resolved to ensure that the emails are delivered successfully.

How to avoid hard bounces in email marketing campaigns?

To avoid hard bounces, it is essential to implement an email verification strategy before sending campaigns. This includes using tools to identify and remove invalid, non-existent or syntax-error emails. In addition, ensuring the quality of registration forms and using real-time verification APIs can prevent invalid emails from entering the contact list from the outset. SafetyMails offers effective solutions for verifying and keeping your mailing lists clean and up-to-date.