How Do You Test If There Is An Email Bounce? What To Do About Them?

March 16, 2022

A perfectly staged email marketing campaign needs only one slip to flop: undelivered emails. When emails cannot be delivered to the desired address, they are bounced back to the sender. The bounced message contains an explanation from the recipient’s mail server, also referred to as the SMTP reply. A common source of grief, email bounces are the email sender’s nightmare. Losing hard work and resources only to receive an auto-reply can be frustrating at the least.

But most importantly, high bounce rates can easily throw you off track. Despite being a repeated concern, email bounces persist in being a hard nut to crack. This is primarily because the issue lies deeper with the bounces you are getting. But how do you test if there is an email bounce anyway?

Let’s find out!

Email sending

Table Of Contents


  • When emails are returned to the sender for various reasons, they are termed email bounces.
  • Email bounces, essentially, imply that your hard-sought out dispatched emails are back to the pavilion. Hence, they have not delivered the message to the desired party, resulting in poor resource usage.
  • Email bounces are a headache to the senders and can break your email marketing strategies.
  • Therefore, it is essential to identify an email bounce and subsequently identify the kind of bounce. This helps to find the appropriate solution. Only then will it be possible to improve the quality and efficiency of any email campaigns?
  • The article ends with a few brief ideas to test for email bounces, With a foreword of how to tackle email bounces.

Differentiating Hard & Soft Email Bounces

So the non-delivered mails can be classified under two categories: Hard and Soft bounces. Each occurs for different reasons and is unique in its way. Once you have tested for an email bounce, it is vital to differentiate the bounce type. Essentially, this helps you avoid the root cause of the non-delivery and hence, reduces overall email bounce rates.

Understanding Hard and Soft Email Bounces.
Image From: Brick Street Software

Hard Bounces

When the message you send returns for a permanent cause, this permanent failure is defined as Hard Bounce, in most cases, invalid email ids, wrong domain/recipient addresses, or simply the non-existence of the receiver's server result in hard bounces.

To be precise, hard bounces occur due to the following reasons:

  • Unauthenticated emails
  • Email/Domain is non-existent
  • Spam/ Sender Reputation Issues
Hard Bounces
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Therefore, the quality of your mailing list plays an exceedingly important role in defying hard bounces. Email providers like Zero Bounce or VerifyBee identify; that is, test the email bounce and identify the invalid address. Subsequently, these platforms stop sending emails to them after the first attempt. Interestingly, VerifyBee cleans your bulk email addresses before you dispatch the message. But in case some of the emails still face hard bounce, you will know instantly.

However, a general misperception that hard bounces cannot be changed causes senders to delete the information permanently. This is the worst possible decision you can make as a sender. Removing customer data is the wrong choice.

For instance, your customer changed the Gmail ISP to Yahoo. But he doesn’t update the information present in your system. So you are unaware of it. If you decide to delete their data after the first hard bounce, it simply means you are letting your customer go!

Instead, you can select the invalid addresses and mark them corrected. Then, either you can reach out to them and ask for the updated address. Or you can always use OneMoreLead to do a lead search use the available information to track the accurate information. With an enriched database, they are one of the best prospect hunting systems, and therefore, even if you are not able to directly reach your customer, you can enrich the customer data.

Soft bounces

As you can predict, temporary failures of emails are called soft bounces. The reasons for non-delivery are quick and can include:

  • Neck-deep full mailboxes. Usually, Gmail offers up to 15 GB of space while Yahoo! offers 1TB. Once the limit is crossed, the mailbox won't allow any new mails to enter.
  • Delays or other such issues on the receiving end. For instance, heavy traffic can sometimes disrupt your mail delivery.
  • Content-based soft email bounces
  • Spam/ poor sender reputation issues.

Explaining Soft Bounces

The last two are concerning issues. If the content within your emails appears suspicious, the mail delivery system will automatically bounce back your message. Hence, design the content and affiliated links with extreme care. Pushing red flags to redirect your message harms your sender's reputation anyways. Moreover, if such implications persist, they can also lead to ISP block.

Similarly, if your sender reputation is compromised, chances are emails dispatched from your domain will remain undelivered. This is because mailbox providers calculate insights to check your domain authenticity and accuracy. If they receive data that have been repeated spam complaints from your domain, your deliverability rates will face a significant blow.

Unfortunately, there aren’t any particular solutions to avoid soft bounces. Instead, the aim here should drastically improve the sender’s reputation. For the second issue mentioned, the Email Service Provider may continue sending the emails until they stop bouncing.

Sometimes, an active email address may go null and void or simply changed, right? As a result, there might be a build-up of unnecessary emails exceeding the storage limit. In such cases, it's imperative to revise the contact information and redirect soft bounces to successful delivery.

Each of these issues can be solved if email bounces are appropriately identified. Testing if there is an email bounce is, thus, a crucial part of your entire email marketing strategy. We will get there. First, let's understand why might there be a sudden increase in your email bounce rates.

Why Might Be There Be Sudden Rise In Email Bounces?

Hard bounces rarely see a steep rise in any given period when emails are sent. Unless you are not validating your email addresses, the chances of undelivered mails are pretty low. Again, a sharp rise in soft bounces suggests that your mailing lists need a revamp. Especially if it concerns your sender’s reputation. This is why we always recommend proper validation and verification of bulk email lists before you start working with them. It is the best decision for your campaigns.

Why Might Be There Be Sudden Rise In Email Bounces?
Image From: FlatIcon

In case of a shaky sender reputation, chances are, ESPs limit your deliverables and result in soft bounces. However, in turn, this saves your reputation on the line too. Persistently sending risky emails may hurt you more than do you good. So, if you see a sudden rise in soft bounces, it's time to divert some attention to derive a better sender reputation.

Since soft bounces require specific solutions, it is essential first to work out the reason and proceed accordingly. And probably the best way to do this is to analyze the bounced results to identify the respective issues. You can even check VerifyBee’s API integration if that suits your needs better and develops a stronger reputation.

Dealing With Abrupt Increase Of Soft Email Bounces

Well, the obvious choice is to revise your mailing lists. How had been the addresses been compiled? When was it recorded? When was the last time you cleaned the email lists? Sending structured, relevant content to the consented audience should be your top priority.

Furthermore, there are certain cases where external reasons might limit you from sending the desired number of emails. One such example can be sending too many of them without the required warm-up. Or if you send emails to recipients who did not give consent to your newsletter or emails, who might, in turn, complain about you. Given the situation, the best solution might be to design the content well and let a supporting platform take care of everything else.

However, there are times when you hit account limitations despite warming up the dedicated IP addresses. This can even occur after users have engaged with your emails! Also, sometimes ESPs make mistakes and wrongly categorize your domain information as suspicious. However, the ESP itself will have a recovery system to solve it. You just have to keep an eye out for such instances.

How Do You Test If There Is An Email Bounce: A Detailed Take

There is no alternative to monitoring and checking the bounces to ensure a healthy email delivery rate and successful program. Hence we bring you three practices that help you understand how you test if there is an email bounce.

Essentially, you would want to see which emails are being delivered and which ones are bounced back. Then, identify the cause of the bounces through the SMTP replies.

The best solution is integrating with platforms that enable you and simplify the process to identify email bounces. Therefore, you can then:

1. Measure Bounce Rates And Identify Changes

Indeed, it is difficult for firms to set a standard value for bounce rates. What's important here is how you differentiate when the percentage is acceptable and worrisome. For example, suppose you are dispatching transactional emails to current users here. A small number of email bounces can be trouble. But, again, if the same case goes for gathering email information for webinars or newsletters, there are higher chances of wrong addresses, and a moderate bounce rate is still ok.


The key here is to measure the bounce rate and keep it below 10%. Moreover, keep an eye out for any abrupt changes, identify them early, and you can save yourself a lot of pain.

A great way to ensure steady bounce rates is to integrate with platforms that offer in-depth reports of your mailing system. With that in place, all you need to do as a sender is review the reports regularly.


2. Partner With Platforms That Offer Support & Insights

Your email provider must differentiate the kind of bounced emails alongside the right insights determining the cause of the bounce. Without learning the whole reason, it becomes tough to troubleshoot the concern and find the right way out.

You should be looking for here that your mailbox provider shows the full bounce explanation. If the provider pinged for status, informing you if the mailbox is already complete, the deal gets a whole lot sweeter.

3. Check For The Kinds Of Email Bounces

The importance of knowing what kind of bounces are turning up cannot be stressed enough. Generally speaking, hard bounces are more concerning than soft ones but knowing the reason for both occurrences is essential. That further determines if the matter is serious or not.

However, regardless of email bounces, always consider spam, reputation, and content-related bounces extremely important. These indicate a severe issue with the overall deliverability of your emails. Moreover, if any specific contact is repeatedly bounced, opt for removing it or finding the correct one. Otherwise, the mail server is highly likely to block your mails anyway.

What To Do About Email Bounces?

Today, there are tons of email verifiers present online. If you want to get started, each of them offers unique services to validate and test email bounces. Such platforms give you a complete analysis of the mails that have been delivered or the invalid addresses. The process includes exporting the bounced email report to the system. Some platforms may automatically correct and resend the message, eliminating the crashed addresses as a hard bounce.

What To Do About Email Bounces?

These reports are a blessing in disguise. You don't even have to worry about the accuracy or anything. Hence, the best way to avoid email bounces is to check the mail addresses, clean the lists every once in a while, and work through the reports for better insights.

Final Word

Everything is excusable, but poor deliverability rates aren't. At least in this day and time, low deliverables and high bounce rates speak volumes for outdated sending practices. Hence, if your campaigns are also suffering miserably, it's high time to break these technical barriers that will get you flying in your desired mailbox.

The key here is the focus on the things that govern email bounces. Factors like a clean mailing list for better sender reputation, little things, like ensuring appropriate content, keeping an updated database, and so on, widely reduce email bounces. Not to mention, such practices also prevent ESP to limit your sending capacities.

Nonetheless, if you struggle to juggle all the concerning factors simultaneously, we might have the perfect platform. With hundreds of apps to integrate with and an existing B2B business database, VerifyBee will not disappoint your needs.

The one platform can work wonders for your email bounces, generating reports, validating email lists, and checking emails before working with them. It has it all. The best customer support system and the most affordable prices, come on guys, that is a rare combination!

Then what are you thinking of! Head out to their website and get email bounces out of your way with a few simple clicks! Start their Free Trial today!

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