How to Understand and Analyze Email Bounce Rates?

Email Bounce Rates

You upload your subscriber list, send out the email campaign, and the number of your subscribers drops. Where did they all go? Experienced email marketers go straight to their campaign report to find out if their audience clicked “unsubscribe.” If they have managed their email lists well, this is usually the only reason subscribers mysteriously disappear. However, to find the real fugitive, you sometimes need to examine your email bounce rates. If your bounce rate is increasing, for one reason or another, fewer subscribers are receiving your emails, therefore, they may be automatically removed from your email list to an inactive list.

What is the email bounce rate?

A bounced email is an email that could not be delivered to the recipient.

Your subscriber’s server bounces the email for a variety of reasons, which we will explain in the next section. If you want to see the bounce rates of your email marketing, you can view them in your email campaign report.

Bounced emails can significantly affect the delivery rate of your emails. That’s because a high bounce rate damages the sender’s reputation if it’s not fixed.

But do not worry about it. We will explain the different types of bounce emails and how you can eliminate them.

How is the bounce rate calculated?

Your Email Service Provider (ESP) will display your bounce rate in the form of a clear percentage. But how does this percentage come about?

To calculate the bounce rate, you simply take the number of bounced emails, divide that number by the total number of emails sent, and then multiply it by 100,

Let us say you sent a total of 60,000 emails and 117 bounced back.

(117 ÷ 60,000) x 100 = 19,5% bounce rate.

What is an adequate bounce rate?

It’s almost impossible to achieve a 100% deliverability rate for your email marketing campaigns, and bounce rates are to be expected. But you should always aim for the lowest possible bounce rate.

A bounce rate of up to 2% is the generally accepted result in email marketing. If you find that your reports are steadily approaching or even surpassing this number, it’s time to review the situation of your email list and take action to optimize it. Your bounce rate can increase for a number of reasons, and more so the older your email list gets.

The distinction of soft and hard email bounce rates

When we talk about email bounce rates, there are two main types you’ll hear about: Soft Bounces and Hard Bounces.

Soft bounce rates

This refers to the rate of soft bounces your email has received. A soft bounce is a temporary issue, where the email gets to the recipient’s email server but is returned as undelivered. Moreover, your soft bounce rate can increase for a number of reasons, including the recipient’s mailbox being full, the email server being offline, or the message file being too large.

Hard bounce rates

The Hard Bounce Rate, on the other hand, informs you about the number of hard bounces your email has received. A hard bounce is when the email cannot be delivered for permanent reasons, such as the address does not exist or the server has blocked you. The email is returned to the sender and cannot be delivered. In this case, your email marketing tool will stop sending emails to these email addresses. A high hard bounce rate is problematic for email deliverability.

Why are emails bounced?

When emails are bounced, it usually has nothing to do with your email marketing software. Your email tool successfully sends the email, but the subscriber’s email server then rejects it for some reason. What are those reasons? We are glad you asked.

Reasons for high soft bounce rates:

Mailbox full: Some of your subscribers’ mailboxes have a limited capacity. When this limit is reached, your email campaign will be returned to you.

Server Timeout: The subscriber’s email server may be temporarily unavailable, overloaded, or undergoing maintenance, and all incoming messages will be returned. In this case, you can try resending your campaign the next day.

Oversized message: This is unusual, but some inboxes have sensitive filters that limit the size of the message. Make sure your email does not contain too many GIFs and images, or your email may be bounced back.

Email account temporarily suspended: If the subscriber has not logged in for more than 365 days or if the server has detected suspicious activity, their account may be temporarily suspended. This means the email will be bounced.

DMARC (DKIM/SPF) requirements: Your email message may not meet the DMARC requirements of the recipient’s mail server for email authentication. Simply put, the server cannot verify the sender of the email.

Causes of high hard bounce rates:

The email address does not exist: invalid emails are the most common reason for hard bounces. This happens when the recipient’s address contains a typo or they have deactivated the address and/or changed providers.

The email is blocked by the recipient’s server: Some corporate, government and institutional domains have stricter spam filter settings.

How to improve your average email bounce rate.

To be clear, both soft and hard bounce rates spell problems. Here we have gathered a list of our 4 best practices to help you to lower your bounce rate.

1. Use Double Opt-In

When collecting subscribers, always use double opt-in forms. This means that after subscribing, the subscriber will receive a confirmation email where they have to click through to confirm their email address. This extra step reduces the probability of spam email addresses ending up in your subscriber list.

2. Keep your email lists clean

The key to avoiding bounces is maintaining a high-quality email list. Use email validation tools like Mailercheck to check and clean up your subscriber lists. When it comes to email address validation, look for tools that go further list validation to provide useful analytics on your email lists. These insights can help you to manage your list and find emails that may be salvageable.

Sometimes a subscriber may not have given you a valid email address. Therefore, always double-check your subscriber lists for typos to avoid hard bounces.

If you switch to another email marketing tool, make sure you only upload your active subscribers. An accumulation of invalid email addresses can highly affect the deliverability of your emails.

To facilitate the maintenance of your email lists, you can choose an email verification tool that provides real-time API verification to check new subscribers before they are even added to your list. This way, you will not have any improper surprises as your email list expands!

Last but not least, you can also ask your subscribers directly for up-to-date information about their preferences so that you send them only the content that interests them.

3. Authenticate your domain

Authenticating your domain is similar to passport control before entering a new country: the border police will check your credentials before letting you through. In email marketing, an authenticated domain legitimizes your account because Internet Service Providers (ISPs) like Gmail, Yahoo, and Outlook can better match the origin of your email.

In addition to authenticating your domain, it’s a good practice to ask your subscribers to add your email address to their address book. 

You can authenticate your domain directly on your dashboard if you use INBOX. Check out our convenient guide on how to authenticate my domain.

4. Be consistent when it comes to sending emails

Consistency is essential. Set up an email cadence strategy so your subscribers expect regular and consistent contact from you. An email cadence is a combination of the number of emails you send in a given time period (frequency), the type of emails you send, and the best times to send your emails.

If there is constant communication between you and your subscribers, the email service recognizes that activity as normal. In email marketing, “normal” is a good thing.

Track your bounce rates with campaign reports.

You can view your bounce rate in your INBOX campaign reports. When you open a campaign report, you’ll see 2 bounce ranges: soft bounce and hard bounce.

In INBOX, a Soft Bounce email address remains active in your subscriber list. However, after 3 consecutive Soft Bounces, it will be converted to a Hard Bounce and will be inactive.

INBOX automatically moves subscribers who are “hard bounce” to the “Bounced Subscribers” category, so they will not receive future campaigns. This means that you do not need to remove subscribers who are in the ‘Bounced’ tab – we will simply do it for you. If you think there is an error with a particular continuous bounce email, contact us and we will check our bounce log.

According to our anti-spam policy, we have the right to suspend your account if the bounce rate is over 5%. You will then be warned and asked to clean up your list using an online email validation tool. This is done to ensure the quality of our servers and the reputation of your sender.

It’s time for fewer bounces and more satisfied subscribers

Your subscriber list is the engine that pushes all of your email marketing. Just like a car needs upkeep to keep it running properly, the health of your email marketing depends on your list being in a good shape.

Subscriber lists with more infrequent bounces make for better deliverability, higher open rates, and a sender call that puts a smile on your face. To make your list the best it can be, think the following:

Keep your subscriber list pure by conducting a bounce email check with a validation instrument.

Use the double opt-in procedure to confirm that you are adding valid subscribers.

Authenticate your email domain and assure a good sender reputation.

Send constant email campaigns to increase open rates and avoid “spammy” content!

Follow your bounce rates with email campaign reports in your INBOX dashboard.

You are on your route to a bounce-free world!