7 Reasons Emails Bounce (And What You Can Do to Improve Your Bounce Rate)

For most of us, the first time we see an email bounce we’re completely at a loss. We’re wondering what it means. And we start asking, “Why do emails bounce?” “Did we do something wrong?” “What are we supposed to do now?”

The truth is, when an email bounces, it’s almost never the sender’s fault. 

But the first step in stopping bounces from happening again is to understand what an email bounce really is.

What is an email bounce?

An email bounce is when a commercial or marketing email is not delivered as intended.

There are a variety of reasons an email may “bounce” but the most important thing to remember is that “bounces” may not only waste your time and efforts but they may also negatively impact your email deliverability. Meaning, if you have a high bounce rate, servers may start to believe that your emails are untrustworthy and may start blocking them automatically.

That’s why it’s important to monitor and clean up those bounced emails on a regular basis. But before we get to that, let’s talk about the types of email bounces.

The two main types of email bounces

There are two types of email bounces — a soft bounce and a hard bounce. While one is temporary, the other is permanent.

What is an email soft bounce?

A soft bounce means that the email address is valid and was delivered to the recipient’s inbox, but it still bounced because the mailbox was full, the server was down, or the message was too large for the recipient’s inbox. 

A soft bounce is generally thought of being a temporary situation because it can be remedied by the recipient cleaning out their inbox, the server being fixed, by you shortening or making your newsletter the perfect lenght.

What is an email hard bounce?

A hard bounce happens when the email is rejected because the email address is invalid or the email address doesn’t exist.

This is a permanent situation and the address should be removed from your list.

Now that you understand the two basic types of email bounces, let’s take a look at six common reasons why emails might bounce.

7 reasons why emails bounce

1. A non-existent email address

If the bounce is marked as “non-existent email address,” the email address could have a typo, or the person with the address may have left the organization.

There’s also a chance that the contact gave a false email address, which can be the case if you’re offering something online in exchange for an email.

In this case, it’s important to review the contacts in this category and see if there are any obvious typos in the email address. If not, try to reach the contacts by other means to confirm the address.

2. Undeliverable email

If bounced emails are in the “Undeliverable” category, that means that the receiving email server is temporarily unavailable, was overloaded, or couldn’t be found.

A server that can’t be found could have crashed or been under maintenance, so this may just mean waiting to send the email to the address again. 

However, if this email address repeatedly bounces on multiple emails, it may mean the server is gone for good.

3. Mailbox full

If your contact has so many emails in their inbox that they can’t receive any more, your emails will bounce back until there’s space for them.

Sometimes, this can mean that the contact is no longer using that email address.

As with a non-existent email address, you may want to follow up with the contact by social media, phone, or mail to check whether the address is valid.

4. Vacation/Auto-Reply

If someone goes on vacation or can’t check their email, your emails to them will bounce.

It’s important to note that, unlike with other bounce categories, this type of bounce means your email was successfully delivered to the inbox.

Carefully monitor how often this email address ends up in this category. If months go by and the person hasn’t returned from vacation, you may want to consider removing the contact.

5. Blocked email

If the email addresses are placed within the “Blocked” category, the receiving server has blocked the incoming email.

This is often the case among government institutions or schools, where servers can be more strict when it comes to receiving emails.

To resolve this issue, you need to get in touch with the contact and ask them to Safelist your emails or, when sent to a company address, request that their system administrators unblock Constant Contact’s IP addresses.

6. Suspended

When an email repeatedly bounces across any email account, Constant Contact categorizes that email address as suspended.

What this means is that the email address in question may be suspended for not only bouncing when you send an email but could potentially be bouncing with other Constant Contact customers. So while you may only be showing one bounce in your report there may be multiple bounces within the Constant Contact system.

7. Other

Bounces that don’t give the server a reason for bouncing are put in this category, so it can mean that the email bounced for one of the reasons above or something else.

It’s important to keep an eye on these contacts, too, to see if the bounces keep recurring.

What you need to do to reduce your email bounce rate

Bounces aren’t good for your email list growth, because of the negative impact on deliverability and the success of your email campaigns.

Monitor your bounces closely. If some addresses continually bounce, it may be time to take the next step.

Remove an email address from your list

When an email bounce is a hard or permanent bounce, you’ll want to remove the address from your list right away.

The addresses that are recommended for removal include:

• Non-existent bounces
• Undeliverable bounces
• Suspended addresses

The best way to remove these addresses from your email list is to unsubscribe them.

After the address has been removed, you can then take the time to check with the intended recipient to see if their address has changed and potentially send them a link to a lead generation landing page that will allow them to signup with their new email address.

Get started addressing your email bounces

Luckily, email bounces show up fairly quickly after you’ve sent an email campaign, making it easy to spot the email addresses that need your attention.

If you haven’t cleaned out bounced email addresses from your account before it might take a bit of time  —  depending on how many subscribers you have  —  but it’s easy with Constant Contact’s “Recommended for Removal” notations.

To get started, export your email report on bounced emails. Then, correct and update any addresses that may have bounced due to typos and resend an email to those addresses. Once you’ve gotten that done, go ahead and clean up those addresses from your email list that have a hard bounce.

After that, it’s just a matter of checking your reports and quickly cleaning out any recurring or hard email bounces each time you send out an email campaign.

Keeping up with your email bounces will ensure you’re getting the most out of your email marketing campaign!