Email Bounce: How To Prevent Email Bounce Back Effectively12 minutes read

If you are looking to grow your business, email marketing is the most effective channel. Building an email list and consistently sending  messages saves time and effort in nurturing your prospects. The email sending success depends on its delivery. If you are able to make it to the recipient inbox your first job is done. This improves your productivity however, the problem arises when the email bounce back.

In 2019, 8.85% of total emails got bounced. According to a study by campaign monitor, the standard benchmark of email bounce rate is 2%. Anything above 2% is a serious issue. However, email bounce back can be reduced by following the best practises.

In this article, we will be describing the significant reasons for email bounce back and how to prevent it efficiently.

What is Email Bounce Back?

Email bounce back is the condition when your emails fail to reach the recipient’s inbox. In this case, your email service provider sends you email bounce back messages about failed delivery and technical details of the failure.

Bounced emails negatively affect your email account by making your account more vulnerable to the SPAM filters. This also decreases your email sender score and deliverability rate. Therefore, it is very essential for an email marketer to know about different email bounces and the methods to prevent it.

Let us go through different types of email bounces and check the reasons why this happens.

Different types of Email Bounces:

Generally, there are three types of Email Bounces:

  1. Hard Bounce
  2. Soft Bounce
  3. General Bounce

1. Hard Bounce

A hard bounce is a type of bounce back email where the recipient’s email address is invalid or non-existing. Mostly it happens when email address is no longer active, or the domain has expired. Hard Bounce also occurs when you enter incorrect email addresses that are totally unknown for the email service providers (e.g; typing down @gmail.con instead of

2. Soft Bounce

A soft bounce is the type of email bounce, where the recipient’s email address is not able to receive your emails temporarily. These email bounces usually occur when the recipient mailbox is full or the recipient’s server is receiving multiple emails at the same time. However these are temporary and get fixed in some time.

3. General Bounce

A General Bounce is the type of email bounce, where the recipient doesn’t receive the email due to the technical limitations of the server. In some cases, receiver’s firewall settings may restrict your emails. This type of email bounce is safe and doesn’t affect your email account and sender reputation.

Why do Email Bounce Back?

Creating an email marketing campaign and then getting a bounce-back message can be a significant loss. Let us see the 8 critical reasons which restrict your emails from reaching your receiver inbox.

1. Invalid Email Address

Your email service provider cannot find the email address if it is already expired or invalid. These conditions force your service provider to bounce back the emails. 

These issues usually arise when you use unverified emails,  buy an email list or use an old email list. This may also happen when you enter an incorrect email address with some typographical mistakes or invalid email format.

In these cases you will receive email bounce back messages “The email account that you tried to reach does not exist” as shown in the image below.


2. Blocked Sender’s IP address

Sometimes email service providers block many IP addresses when they suspect spamming activities. In this case, your emails won’t be able to cross the filters of the recipient’s server, resulting in an email bounce back.

Free email  providers like Gmail, Yahoo, Zoho, Outlook, AOL share a single IP address with many users. When any shared user performs a  spammy email campaign, other email users with shared IP addresses get affected. So if you are doing a campaign, avoid using free emails.

3. Email blocked by receiving server

Many servers block a particular email address or domain if they suspect any malicious activity. When the sender tries to send an email to those recipients, their email gets bounced.

It ultimately decreases your sender reputation and email deliverability.


4. Receiving server is overloaded

Your email cannot reach the recipient if the receiving server is overloaded. In this case, the server won’t be able to receive any incoming requests, and you get a bounce back message. 

This is a soft bounce, usually a temporary issue that gets solved in some time.


5. Receivers inbox is full

Every mailbox has some standard storage limit. If the recipient has not cleaned up his mailbox, then it has a chance of your emails getting bounced. This is a rare issue which usually happens when the email address is active but doesn’t have free space to take new emails.

This is again a soft bounce and is considered as a temporary issue.


6. Low sender reputation score

The sender reputation score is one of the major factors that affect your email deliverability and bounce back rate. A low sender reputation score diverts your emails towards the SPAM filters or bounces back. Overally, this decreases your sender reputation score and increases the email bounce rate.

7. The recipient has added an auto-reply

If a recipient is not available to access the email, then he sets an auto-reply to all the incoming emails. You receive an informative reply from the receiver. This is also considered as a type of email bounce back, but it does not affect email deliverability or sender reputation score. 


8. Email size is too large

Email size is an important factor for email bounce back. Some Email service Providers restrict the emails of huge size due to their privacy concerns. There are also some Email Service Providers that allow only text emails.

In these cases, sending emails with rich text and images make your email bounce back. It has to be taken into consideration and draft the email in an optimized manner.

We hope you understood why email bounce back, now it’s time to find how to prevent it in the first place.

Implementing the best practices effectively against email bounce back helps your emails reaching the recipient’s mailbox. Having said that, let’s dive deep and learn how to stop bounce back emails with tried and tested, proven techniques.

How To Prevent Email Bounce Back?

1. Use double opt-in

Double opt-in is one of the best methods of building a valuable email list. Once a user registers with your mailing list, ask them to verify their account. This provides you an assurance about the authenticity of their email address. This simple process will help you to reduce email bounce rate drastically.

2. Maintain a clean list

Update your email list periodically. The email addresses usually expire with time, which increases  the chances of email bounce. It is better to use an email verification tool to verify your email list before scheduling any email campaign.

Maintaining a clean list makes your email list healthy. Scheduling an email campaign with these lists provides you with better deliverability and decrease in  bounces.

Pro Tip: Remove the inactive email accounts from your main list.

3. Double-check for typos

The best way to prevent typographical error is using the double opt-in method listed above. Still, if you are manually building a list then these types of mistakes are prevalent.

You need to be very careful while listing down your email address before sending your email campaign. We have seen many email bounce with users because they type in place of

It is highly recommended to double-check your email address everytimẹ to avoid simple typographical mistakes like this.

4. Authenticate your email account

Authentication is a process done to maintain your sender reputation, which indirectly helps you to reduce email bounce back rate. There are three types of authentication processes to improve your email deliverability

  • SPF
  • DKIM

These techniques help the receiver’s server to check the authenticity of the email received. When the receiver’s server gets these records in your email, they provide a clean chit to your message and reduces your email bounce rate.

Bonus: Learn how to Setup SPF and DKIM and improve your email deliverability.

5. Don’t spam your content

There are various factors that makes an email content Spammy that increases your email bounce rate. Check out the below pointers to build a non spammy  email content which will give you better results:

  • Do not add any SPAM triggering words in your email content. There are certain SPAM triggering words which are blacklisted by various Email Service Providers. If you add words like FREE, OFF, 50% in your email body, the receiver’s ESP assumes the email to SPAM or promotional content. On frequent usage of these words, the emails bounce back.
  • Do not use too many links in your emails. Adding too many links in your emails are suspected to be an act of phishing activity and the receiver server bounces back the email.
  • Maintain 60:40 text to HTML ratio. Rich graphics and beautified HTML emails are usually promotional and pure text emails are damn boring. Maintain a mixed ratio between the text and HTML to get the best performance.
  • Avoid CAPS, BOLD and Exclamation marks. Content with too many characters in Caps or bold are intended to be spammy and should be avoided.

If you follow the above pointers in your email content, chances are less of your emails being considered as SPAM and will reduce email bounce rate.

6. Maintain time frame between consecutive emails

You should always maintain some time gap between two consecutive emails in an email campaign. All email service provider’s algorithms believe that no human can send multiple emails at one go. When this happens, the algorithms assume it to be a non-human activity, and your emails start to bounce.

The ideal time gap required to be maintained between two emails is 90 seconds. You can use an email automation tool like SalesHandy  for your email marketing campaign. It will help you set the time gap between your emails .

7. Keep an eye on your sender reputation score

The sender’s reputation score is a standardized value provided to the domains to check their email activities. A low sender reputation leads to email bounce back, emails going to spam box, and sometimes blocking your account.

Along with following the best practices of sending email campaigns, it’s  also important to keep an eye on your sender reputation score. There are many free tools like Sender Score, which allows you to check your score.

8. Send emails consistently

You should always keep an engagement with your email subscribers. When there is a constant flow of messages between two accounts, the receiver server gets an assurance of the quality of the email conversation. The receiver server stays aware of the email activity which makes your account less vulnerable to email bounces.

9. Avoid Free Sender Domains

While using a free email sender domain (e.g.,,, etc.), you are not allowed to authenticate your email account. This makes your account more contagious to spam filters, and your emails bounce back while doing an email campaign.

Always use an authenticated business domain for email campaigns to get the best results from it.

10. Don’t exceed your daily sending limit

Every email service provider provides you with a certain email sending limit. If you try to send more than your limits in a day, your emails start to get bounced. 

It is suggested to keep a look on how many emails you are scheduling in a day and plan accordingly. If you exceed your daily sending limit frequently, you may end up permanently blocking your account.

To get a record on  your daily sending limits, it is suggested to consult with your Email Service provider on a regular basis.

Final Words

Marketers spend a lot of time, effort and money in email marketing. Constant email bounce might break the success of the campaign. Following the above methods and prevention techniques will always help you with the best results to reduce the email bounce rate. 

Along with the best practices, you also need to use an email campaigning tool like SalesHandy, which automates your email campaign and stops your emails from bouncing back.

If you found this post helpful to reduce email bounce rate, please share it on your social media followers. 

By Rajendra Roul

Rajendra Roul works as a content marketer with SalesHandy, where he writes and edits the sales guides and articles. He is an avid researcher, learner, and an analytical guy. After flipping the coin, he loves to read books, play social games and travel around. He believes knowledge is the only source to achieve victory.

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