Understanding Email Bounces and How to Rid them from your Lists

Understanding Email Bounces and How to Rid them from your Lists - mailmonitor

You’ve spent countless hours designing and perfecting your campaign’s emails, and you’re finally ready to distribute them to your subscribers. Then, you clicked on the send button and felt that sense of accomplishment from doing a job well done.

But as you watch the analytics coming in, you notice a climbing metric: your amount of email bounces. As your bounce rate continues to go up, you begin to ask, “What did I do wrong, and what causes my bounce email rate to increase?”

As an email marketer, you’re probably aware of bounces by now. Email bounces happen all the time, but they shouldn’t be something that will continue to plague your campaigns in a significantly negative way.

To help in understanding email bounces and how to rid them from your lists, let’s first understand what they are.

What Is Email Bounce?

Simply put, an email bounce is a message that cannot be delivered to its recipient. There are several reasons why email servers can’t send an email. Two common factors are when your users type in the wrong address or when the mailbox of the contact is down.

Each time a server rejects a message, it will inform the sender of the bounce by providing them with a non-delivery report. Although the appearance of these bounced messages will differ depending on the inbox provider, they do share the same information.

Typically, a bounce would include the following:

  • A message informing of the bounce error

  • Details on the date and time that the email bounced

  • Information containing the unique ID of the bounced message

  • The hostname and IP of the server

  • SMTP error message

What Are Soft Bounce and Hard Bounces?

There are two categories of bounced emails that every email marketer should know about: soft and hard bounces.

Let’s take a look at each one to understand them in detail.

Soft Bounce

A soft bounce message happens when an email experiences a temporary delivery problem. It’s considered as the softer version of bounces hence its name.

Most email service providers don’t notify users when soft bounces occur, as these will continue to be resent until they get through. If the email message still can’t be delivered even after a set time, then the soft bounce will be converted into a hard bounce. This is when the server will notify the sender of such failure.

Hard Bounce

A hard bounce is the more serious concern of the two categories of bounces since it indicates a permanent issue that prevents message delivery. There are several reasons for a hard bounce to occur which will be discussed below.

Email marketers should take hard bounces seriously since this can increase their bounce rate and cause their sender reputation to take a dive. As soon as a hard bounce is identified, it’s best to remove that specific recipient’s email address from the list.

Since hard bounces are permanent, it’s best to eliminate the addresses that caused them as soon as possible.

Why Do Emails Bounce?

Given that email bounces can significantly affect one’s deliverability and reputation, it’s important to know what causes them to happen in the first place. This is especially crucial since the success of your campaigns highly depends upon reducing your bounce rates.

Here are the main reasons why your messages may bounce:

You Are Sending to an Invalid Email Address

Bounced messages that come with notifications about non-existent email addresses could mean that they are no longer actively being used by their old owners. It could also be due to a typographical error made upon input.

However, there are also instances of hard bounces that were caused because contacts provided incorrect or false addresses.

It’s best to review each email address that resulted in a hard bounce and either remove them from your mailing list or find another way to contact and confirm their details.

The Receiving Email Server is Unavailable

When a recipient’s mail server is unavailable, it will send a notification saying it’s undeliverable. It could be due to the server being overloaded or under maintenance.

When these instances happen, the servers usually resolve the issue and allow emails to pass once they are fixed. Yet there are also instances of repeated bounces even after some time has gone by. This could mean that the mailbox server has shut down permanently.

Your Email Has Been Blocked by the Receiving Server

When your emails come with a “blocked” label, this means that the servers of your recipients have blocked your messages from getting to their inboxes. Corporations, government institutions, and educational facilities often have networks that have mailbox filters that can be quite strict in terms of allowing emails in.

IP addresses can be blocked by default, especially from those coming from outside of their organization. One way to fix being blocked is to request access from their respective system administrators.

Your Recipient’s Inbox is Full

Another common reason email bounce rates going is that your subscriber’s inbox is currently full. This means they are unable to receive incoming messages and will result in any email that is intended for them to bounce.

The good news is that these mailboxes will start accepting emails once they have sufficient space to do so. However, it’s still best to be cautious and separate these bounced email addresses or remove them from your list to avoid problems in the future.

How to Reduce Your Bounce Rate

Having a high bounce rate isn’t an ideal statistic for any email marketer. If you’ve started noticing such metrics beginning to increase, then you need to make sure you can find a way to reduce it to an ideal level.

Here are some of the best tips so consider that will help minimize your bounce rate:

Make Sure to Clean Your Email Lists Often

One of the best ways you can ensure that your email bounce rates are kept at a minimum is by ensuring that the lists you use are cleaned regularly. Maintaining appropriate email list hygiene is important since it helps eliminate contacts who are inactive or not interested in reading your content.

When you clean your email databases often, you have a higher probability of increasing your open rates, deliverability rates, and engagement rates while reducing bounce backs. All of these add up to help give you a greater sender reputation which is always beneficial for marketers.

Your Domain Should Be Authenticated

There are three major protocols used to authenticate emails: SPF, DMARC, and DKIM. Unfortunately, a significant portion of domains is still without these email authentication standards in their toolsets.

The primary benefit of authenticating your domain is to avoid being flagged by the security systems of your recipients. Besides improving sender reputation, it also enhances email deliverability rates since it will ultimately lead to reduced email bounce.

Take Advantage of Double Opt-In

Double opt-in is an approach in email marketing that requires newly-subscribed contacts to confirm their email addresses as soon as they sign up. This allows marketers to minimize the amount of fake or faulty information provided during the subscription process.

Compared to single opt-in, the double opt-in method is far more superior and secure. It helps people know that the valid email address used in signing up comes from a legitimate and monitored inbox.

If you wish to minimize your bounce rate, double opt-in can give you that significant reduction that you’re looking for. It is extremely beneficial to brands that aren’t focused on growing their audience but want to lower their bounces for increased deliverability.

Segment Your Email Lists And Personalize Your Messages

Consumers today are leaning towards brands that are capable of providing them with personalized experiences. The same is true in email marketing. When you personalize messages, it provides significantly better results than sending generic emails.

One of the best ways to get started with personalization is through your email campaign sequencing. Here is a good example:

  1. Send a welcome message to your contacts introducing the brand and its offerings.
  2. A trigger activates upon engaging with the email and sends out the next appropriate message in your sequence.
  3. But if the recipient doesn’t open the message, you can send a reminder with a compelling subject line to catch their attention.
  4. If the contact still doesn’t engage with your email, you can send them another with a deal that is difficult to pass up.

Segmenting your email lists allows for more personalized and effective communication to your subscribers. It also ensures that your messages have the highest probability of landing in inboxes and being opened by the recipients.

Design and Apply Engaging Email Content

Once your recipients open your emails, the next thing that they’ll go through is the content within. If your content was poorly written and designed, you can’t expect people to stick around or accomplish your desired action.

Most people would ignore emails with bad content and just move on to the next. Furthermore, messages that take their time to load will deter your campaigns.

Instead, you should create and apply engaging content in your emails as much as possible. From the copy that you include to the media, you want to make sure that your email content is brief and valuable yet to the point. Your goal is to get people to complete a specific activity you have in mind and not delete your messages even before they engage with them.

Leverage the Right Email Marketing Software

Having the appropriate email marketing software at your side can help you avoid most of the previously mentioned issues regarding bounced emails. There are many options available in the market today but the ones you should avoid are the free providers.

Instead, you should go with reputable brands like MailMonitor that can help marketers keep an eye on the performance of their campaigns through various features.

MailMonitor is an email software platform that provides users with everything they need to monitor their email deliverability and reputation. It offers features such as spam filter testing, blocklist monitoring, reputation tracking, and inbox monitoring.

MailMonitor is even better than others because it’s readily compatible with most email service providers. You can quickly integrate the platform with the likes of MailChimp, HubSpot, Salesforce, GetResponse, Constant Contact, ActiveCampaign, and Sendinblue.

If you’re unsure whether the platform supports your mailbox provider or not, then you can always schedule a free demo to find out.


Email bounces are a means for your email service provider to let you know that your messages haven’t reached their intended destinations. When a bounce happens, it’s usually accompanied by a notification informing users of the reason why it occurred.

There are several reasons why emails bounce, such as:

  • Sending to an invalid email address

  • The receiving server is unavailable

  • Your subscriber’s server just blocked your message

  • The inbox of the recipient is currently full

A bounce is never a good thing for marketers, and having too many of them can decrease your key email metrics such as sender reputation and deliverability rate. The good news is that there are ways you can incorporate right now to reduce your bounce rate and ensure your emails have the highest chances of landing in their designated inboxes.

By following the tips provided in this post, you should now be equipped with the right information on how to go about reducing your bounce rates to improve your email campaigns.

We offer tools and features that help you reduce negative rates and enhance the deliverability of your marketing campaigns