What are Bounced Emails and How to Avoid Them

Did you know more than 4.26 billion people use email worldwide? From a business perspective, email provides a direct, more intimate channel to connect with a target audience. The marketing strategy offers an impressive return on investment of $36 for each dollar spent.

However, not every email reaches the inbox of your recipient. In this post, we’ll talk about all the possible reasons for an email bouncing back. We’ll also dive into how you can avoid email bounces and maximize your deliverability as a marketer.

Let’s dive in.

What is a Bounced Email?

Simply put, a bounced email is an email that does not reach the recipient’s inbox. How do you know about it? You get an automated email with the piece of information that your email didn’t reach the inbox. It can be frustrating to experience an email bounce, but the technology actually benefits marketers as it keeps spam senders at bay. Email bounces can hurt your reputation as a sender and email marketer. This is because when your email bounce rate gets over 2%, your IPS (Internet Service Provider) might think you’re a spammer, which will be bad for your sender's reputation.

Why? Because spammers generally send bulk emails without consent from the recipients, which results in email bounces.

ISPs calculate sender reputation and use it to identify spammers and legitimate senders. So, if your emails bounce back, your reputation takes a hit, even if you aren’t a spammer. You want your bounce rate to be as low as possible, ideally, zero. Great than 2 bounces out of 100 emails sent will hurt your sender's reputation and, in turn, deliverability.

Below, we dive into the reasons for an email bounce, allowing you to stay away from such practices.

Reasons for Email Bounces

It can be tricky to find out the exact reason for an email bounce since there are a lot of them. Here are the most common ones.

Invalid Address

When the email address you want to reach is invalid, your outgoing email will bounce. This can happen for two reasons:

1. You make a typo while entering the email address
2. They’ve provided you with the wrong email address

This is why it’s important to make sure the emails on your list are valid. When capturing email addresses for your newsletter, make sure not to accept invalid emails.

Full Mailbox

The person who’s supposed to receive your email may have a full mailbox. The old emails may have piled up and they’ve run out of the allotted space. In that case, they won’t be able to receive any new emails.

Message Too Large

An email can also bounce when it is too large or has large attachments, for instance, an HD video file or a list of high-resolution images.

Recipient Doesn’t Exist

Sometimes, the recipient you’re trying to reach does not exist. For instance, let’s say you’ve sent an email to [email protected], but there’s no John associated with that domain. However, note that catch-all domains, as the name suggests, receive all emails sent to them. You may still experience bounces though.

Low Sender Reputation

A diminished sender reputation can also be a cause of email bounces. You don’t have to be a spammer to get into the bad books of your Internet Service Provider. If you don’t maintain your email list, your outgoing emails may start bouncing back.

Invalid Domain Name

Of course, if the domain name of the recipient isn’t correct or is invalid, you’ll end up getting a bounced email.

The Recipient blocks you

If someone blocks your email, you may receive a message that you were blocked. In other cases, your email will simply bounce.

As an email marketer, you want to make it easy for your list to unsubscribe to your newsletter whenever they want. The best practice is to add an unsubscribe link at a visible location within your email.

Blacklisted Email

You could end up damaging your sender's reputation by sending emails to honeypots. Honeypots are email addresses that attract spammers. Sending emails to these addresses, even if you’re not a spammer, can put you on the backlist, resulting in email bouncing.

DMARC Authentication Failure

Google and Yahoo have recently rolled out their new guidelines for mass senders. If you’re sending more than 5000 emails, you need to authenticate your domain. DMARC stands for Domain-based message authentication, Reporting & Conformance. If you don’t authenticate your domain, your emails will either end up in the spam folder or bounce back.

DNS Failure

Your domain name system (DNS) can go offline for any reason such as malfunctioning of the data center. DNS failure is normally a temporary issue, but it can cause email bounces.

Disposable Recipient Email

Sending an email to a disposable email address is another reason for bouncing. Disposable emails are temporary emails that stop existing after a few hours or days.

People normally create disposable emails because they don’t want to give out their primary email address. If you send an email to a disposable address, it’ll bounce back. Therefore, keeping your email list clean from these email addresses is crucial.

If someone isn’t providing their real email, they aren’t interested in whatever you have to offer, so keeping these emails off your list is the right thing to do.

Can Bounce Emails Reach Recipients?

If you get a bounce message, it means the email you sent did not reach the intended inbox, so you should consider it not delivered.

However, this doesn’t always mean you should not send emails to that address in the future. There are two types of email bounces:

1. Hard bounce
2. Soft bounce

Let’s talk about both.

What’s a Hard Bounce?

Hard email bounces indicate permanent failure of delivery, meaning that your email hasn’t and will not reach the recipient. This means if you ever experience a hard bounce, you should remove that email address from your list.

Hard bounces can occur for several reasons, including:

• Invalid or non-existent email address: This happens when the email address provided by the recipient is incorrect, mistyped, or no longer active. It could be due to a typo, a temporary issue with the recipient's email server, or the recipient having closed or abandoned the email account.
• Domain name does not exist: If the domain name in the email address doesn't exist or is misspelled, the email will bounce. It could be due to a typo or an error in entering the domain.
• Email server issues: The recipient's email server might be experiencing technical problems or maintenance, preventing the delivery of emails. In such cases, the email will bounce back to the sender.
• Blocked by recipient's server: Some email servers employ strict spam filters or security measures that may block incoming emails based on certain criteria. If your email gets flagged as spam or triggers any of these filters, it may result in a hard bounce.
• ISP restrictions or blacklisting: Internet Service Providers (ISPs) maintain lists of known spammers or problematic senders. If your email or your email service provider's IP address is on one of these lists, the recipient's email server may reject the email, causing a hard bounce.

What’s a Soft Bounce?

Soft bounces indicate a temporary delivery failure. This means your email may have bounced at the moment, but it can reach the intended inbox in the future. Common reasons for soft bounces include:

• Mailbox is full: If the recipient's mailbox is approaching its storage limit but hasn't reached it yet, the email server may temporarily reject incoming emails. This is considered a soft bounce because once the recipient clears some space in their mailbox, future emails can be delivered successfully.
• Temporary delivery issues: There could be temporary issues with the recipient's email server or network that prevent the email from being delivered. These issues could include server downtime, network congestion, or maintenance activities. Once the issue is resolved, the email will be delivered successfully.
• Oversized email: If the size of the email message exceeds the recipient's email server's limits, it may result in a soft bounce. The server may reject the email temporarily but allow it to be delivered if the size is reduced or if the server's limits are increased.
• Vacation or auto-reply settings: Some email accounts are set up with vacation or auto-reply messages. When an email is sent to such an account, the server may respond with an automatic reply indicating the recipient's absence. This is considered a soft bounce because the email is not directly delivered to the recipient's inbox.
• Greylisting: Greylisting is a technique used by some email servers to combat spam. When an email is received from an unknown sender, the server temporarily rejects it with a request to resend the email later. Legitimate email servers will usually try again, and upon the second attempt, the email will be delivered successfully.
• Content filtering: Some email servers employ content filtering mechanisms that analyze the content of incoming emails. If the email triggers certain filters or contains suspicious content, the server may temporarily reject it. This can include emails with certain keywords, attachments, or formatting that match the server's filtering rules.

Email service providers generally try to deliver these emails in the next 72 hours window, after which, the email will not be delivered.

Reasons for Gmail Emails Bouncing

If you’re an email marketer with a decent number of Gmail contacts, you may have experienced an increased bounce rate. You’re not alone.

In an effort to counter spam and other security threats, Google has been deleting inactive Gmail accounts. To keep your list clean from dormant accounts and minimize your bounce rate, run a validation test.

Reason for Yahoo Emails Bouncing

Yahoo is the second most popular email service provider after Google. The tech giant started deactivating and removing inactive accounts in 2019. This means if you’re experiencing an increased bounce rate recently, there’s a good chance your list has some inactive Yahoo addresses.

Maintaining your email list and validating it once in a while can help you minimize the bounce rate.

What’s an Acceptable Bounce Rate?

Your bounce rate should be as close to zero as possible. But, is there an acceptable upper limit? It depends on the size and industry of your company, however, it shouldn’t surpass the 2% mark. This means if your bounce rate is over 2%, you might want to re-evaluate your strategies.

How to Prevent Email Bounces

Here’s how you can make sure your emails reach your recipients’ inboxes.

Avoid Spam Filters

Sending spam emails has several drawbacks; an increased bounce rate is one of them. The problem is even if you’re not sending spam emails, you can end up triggering spam filters. All it takes is a few spam complaints by your recipients.

Here’s how you can avoid engaging spam filters and keep your emails from bouncing back.

Don’t Use Trigger Words

Some words may trigger spam filters, such as “Free”, “Guarantee”, and more. Generally, you want to avoid using sensational language in your emails.

Use a Custom Domain

If you’re still using a third-party email address like Gmail or Yahoo, you’re inviting trouble. When you send a bulk email with Gmail or Yahoo, you use their sender reputation. To protect that reputation, these platforms can mark any attempts to send bulk emails as spam.

Authenticate Your Domain

In order to reach the inbox of your recipient, you must also authenticate your domain. This is especially important after the recent deliverability updates by Google and Yahoo.

Keep Your List Clean

Probably the most common cause of email bounces is an unclean and unmanaged list.

Validate Your Database

Email validation helps you filter out inactive emails, keeping your list clean. An email validation tool does this by eliminating hard bounces. Find a good validation service, upload your list, and get a clean list.

Validate in Real-Time

Running a validation test on your email list helps you keep it clean and relevant. However, there’s an even better way to ensure your emails don’t bounce back.

It’s real-time validation. You can use an email validation API to make sure every new lead you gather is valid.

Connect an API with every opt-in form you’re using to collect email addresses. This keeps irrelevant and invalid contacts from entering your list.

Segment Your List

Effective segmentation allows you to write and deliver content that your audience wants to read. So, instead of sending every email to all subscribers on your list, use segmentation.

For instance, you can have different audience segments based on:

• Age
• Gender
• People with kids
• Location

In addition to that, the type of content you serve to an existing customer and someone who hasn’t yet bought from you should be different. As a result, your content will be highly personalized, maximizing the chances of engagement and minimizing spam reports.

Be Consistent

Your subscribers might forget that you exist if you don’t stay in touch with them. Having a consistent emailing schedule helps you stay top of mind and drive engagement. This will keep your list active and require less cleaning.

Use a Captcha

A captcha system helps you keep bot accounts and fake email signups at bay. Install a captcha on every signup form to capture human email addresses only.

Use Relevant Opt-Ins

If you’re using a lead magnet like an ebook, special offer, or any other incentive, make sure it’s based on your audience’s interests.

The content of your emails should also be industry-relevant or around your brand.

Conclusion

When an email fails to deliver to the recipient’s inbox, it’s called a bounced email. An email can bounce for several reasons, the recipient’s address being inactive or invalid is one of the most common ones. A high email bounce rate means a lot of your emails aren’t reaching the intended recipient. The problem is that bounced emails are bad for your sender's reputation. And, a bad sender reputation can further hurt your email deliverability and overall ROI.

Here’s a quick recap of what you should do to keep your bounce rates to the minimum:

• Keep your list clean
• Avoid spam filters
• Segment your list
• Use captcha
• Use relevant opt-ins
• Be consistent with emailing