All About Hard Bounce & Soft Bounce

Hard bounce and soft bounce

A bounce is encountered when an email fails to get delivered to the recipient's email server. This can be a big problem for an email marketer as it reduces the number of prospects reached out. In this blog, we will understand what are hard bounces and soft bounces and how they affect your email marketing.

Table of content

What is an email bounce?

When the recipient's email server refuses to accept your email message and sends it back to you, then it is termed as an "email bounce." It means they could not be delivered successfully to the inbox of recipients.

The recipient's server sends an automated bounce message, called a Non-Delivery Report/Receipt (NDR), in return. It contains the details of the particular problem with that email delivery. The recipient's tab of sent marketing emails holds complete information regarding the bounce type and server response.

The bounce rate shows how good the mailing list is during email marketing campaigns. It has an immediate impact on your reputation as a sender. It is an important parameter that you must track during email marketing.

Types of bounces

Now there are two kinds of bounced emails:

  1. Hard bounces

  2. Soft bounces.

Soft bounce

A soft bounce is a temporary failure in the deliverability of an email. You can resend the email to the recipient in the future.

The temporary delivery issues may include large content of the email, a full inbox, a down server, or other technical problems.

Hard bounce

A hard bounce is a kind of permanent failure in the deliverability of an email. In these emails, the user cannot deliver the email to the recipient due to permanent reasons.

Some of the permanent problems can be the recipient's false email address or wrong domain.

If you are conducting an email marketing campaign, you must remove all these addresses because the recipient's server won't accept any email. And since email deliverability might affect your domain reputation, it is essential to clean your email lists.

What are the main reasons for email bounce?

Email bounces can be because of the following reasons:

1. Imported list errors

When a user imports the email list in the CSV format, there are chances of incorrect information in the email addresses. Hence, it requires proper formatting beforehand.

2. Emails sent through free email providers

Using free email provider services such as Yahoo and Google will result in DMARC authentication problems. As per the updated DMARC policies, private business domains should be used for sending emails during the email marketing campaign.

3. Old email list

You must update your email list from time to time. Otherwise, there is a high probability that some email addresses of the old list may have been abandoned or converted into recycled traps.

4. Unrelatable and inferior quality emails

Quality makes a huge difference in preparing the best-suited email list and, further, email marketing. You need to do a quality check for the scraped or email list you purchase. Though hard bounce is a permanent deliverability failure, checking the soft bounces is crucial to ensure your sender's reputation remains intact.

The main reasons for soft or temporary email bounces are as follows:

  • A full mailbox

  • The large message of the email

  • Server unavailable

  • The email couldn't pass the spam filter

  • Temporary suspension of the email account

The hard or permanent bounces cause the real problem as the user cannot resend the emails.

The main reasons for hard email bounces are:

  • Invalid email address or a typo in the address

  • The email address no longer exists

  • The email recipient's server is blocking the sender's server.

Acceptable Email Bounce Rates

The higher bounce rate can spoil your reputation. Thus, you must keep this rate in check. The quality of your contacts list affects this bounce rate. It varies from one service provider to another.

A low bounce rate (up to 1%) reflects a current, maintained list with real and active subscribers. The acceptable bounce rate is approximate 3% to 5%. Your account can get blocked if you have a hard bounce rate above 10% in most ESPs. Meanwhile, a high bounce rate is usually higher than 3%.

Where can you search for the email 'unsubscribes' list?

The Email Marketing and CRM applications have a complete email suppression list due to hard bounces and repeated soft bounces. You can check the list in the Email Marketing application by checking up the 'Unsubscribes' button.

How to reduce Hard and Soft Email Bounces?

In any email campaign, the bounces need immediate attention. High bounce rates have many disadvantages, for example, suspension of the account. It may lead to an adverse impact on marketing and your senders' reputation. Therefore, you should adopt the given measures to reduce email bounces.

1. Double opt-in list

You can ask your users to click on the email verification link before adding them to the list. It is known as a double opt-in process. It helps deal with fraudulent emails, thereby ensuring the validity of emails and further monitoring the inbox.

2. Clean your email list

You should clean your email list regularly. It will help in decreasing the chances of a temporary and, at times, permanent account ban.

3. Never spam

Your message shouldn't be spammy; otherwise, providers like Google and Yahoo with inbuilt spam filters will directly forward it to the spam box.

4. Send emails regularly

Try to send emails at regular intervals. Some choose to send two to three times a week. However, it's essential to keep an eye on the overall performance of the email campaigns.

5. Remove bounces

Various websites provide adequate services to remove email bounces. You can sign up with them and work on conducting a successful email campaign.


Email bouncese can be the deciding factor for a good sender reputation and email delievrability rate. These two factors influence the overall performance of your email marketing campigns. At Mailmodo, we ensure that our client's bounces are lowest and that bounce-suppression is readily available to improve the campaigns. If you like to learn more about this, feel free to reach out to the Mailmodo team.

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