Email Bounces: Everything you Need to Know

Whether it’s selecting the right graphics, segmenting your audience, or writing relevant email copies - you’ve done everything for your email campaign! After all these efforts, are your emails still getting bounced?  

Truth be told, email marketing is tricky. Many factors impact the success and failure of the marketing campaign. One such factor is the Email Bounce Rate. While bounces are entirely normal and you can ignore a few bounces, but the problem starts when they start to pile up.

And, as hard as it seems, you can’t avoid bounces altogether. Well, it’s the truth, but the good news is – you can maintain a healthy email bounce rate! 

Below we’ve rendered everything you need to know about email bounces or bounced emails. So, if you want to keep your emails flowing, continue reading.

What Is An Email Bounce?

Bounced email is an email that isn’t delivered to the recipient. Basically, a bounced email means that the message has not been delivered, and for this, you’ll get a notification of non-delivery.

There are many reasons for bounced emails, some of which are:

• Bad IP address: there are chances that the IP address you are using for sending emails could be blocked. It can be blocked if you are suspected of email fraud or spamming.

Avoid this problem by using high-quality marketing techniques and make sure you never buy or rent email lists. 

• The Recipient’s mailbox is full: Many email providers allow limited storage. So, as soon as the inbox gets full, it will bounce all the future messages.  
• The subscriber blocked you: If someone no longer wants to hear from you, the recipient can block you.
• The server is overloaded: Even the most powerful server cannot handle so much traffic. The email could bounce due to an overloaded or unavailable server. This type of case generates a soft bounce.
• The subscriber’s email address is invalid: If the recipient’s email address is invalid, it could result in a bounce.
• The receiving server doesn’t trust your content: Your email should be credible enough so the recipient could trust it.      

What are the contents of a bounce message?  

The bounce message contains the information, which will help you in identifying the reason for email delivery failure. It includes:

• The date and time the email got bounced
• The mail server that bounced it
• The reason for the bounce along with the RFC code

Types of Bounce

Soft Bounce

Soft bounces are temporary reasons an email cannot be delivered. This type of bounce means that the email address was valid, and the email message has reached the recipient's mail server. But delivery has prevented the word from reaching the recipient.

So, the common reasons for bounced email could be:

• The Server was Down: There are many instances when maintenance periods on messaging services trigger temporary bounces. After finishing the maintenance, your server delivers the email.
• The mailbox was Full: If your email contact has a full inbox, the server can reject the email. These are usually temporary failures. Once the space is available, the server accepts the email for delivery. In some cases, full mailboxes can cause immediate hard bounces.
• Overly broad message: If the message is too large for the recipient system, it could also result in a soft bounce.
• Greylisting: In this type of spam filtering, emails get delayed purposefully. When the server tries to send the message, the recipient's server issues a temporary error response (421).

After some time, the server attempts to resend the email, when the recipient's server accepts the email.      

Hard Bounce

A hard bounce is when the message has been permanently rejected.

And, you shouldn’t take hard bounces lightly. As soon as you see a hard bounce from an address, immediately remove that recipient from the subscriber list. 

• Unknown Domain Errors: This bounce happens if the domain you used either cannot be resolved by DNS or did not exist. Domain errors are not so common, and error messages vary considerably.
• Unknown Users: Unknown users are a major cause of hard bounces. There are a variety of messages for these issues, which may include:
• No mailbox by that name is currently available
• No such user available
• Recipient address rejected
• The recipient cannot be reached
• Spam Filtering: If your domain has a history of forwarding spam emails or your IP is on a blacklist, your email may be blocked.
• Email Policy Filters: Along with spam filtering, few systems may use email policy filters. These filters scan both outbound and incoming emails.
• Misconfigured Recipient Server: the Wrong configuration on the server of the recipient can cause bounces. In this situation, you may or may not get any specific error but a non-delivery report.
• File Attachment Issues: Most mail servers limit the type and size of attachments for performance and security. As with email policy filters, this filtering can be both outgoing and incoming. The most frequent email bounce is due to an overly large attachment.

When a Soft Bounce Becomes a Hard Bounce

When an email address returns a soft bounce five times, without opening or clicking during this period, the address automatically gets converted into a hard bounce.

And, when a subscriber interacts with an email, the number of software bounces recorded for that address (if any) is reset.

How to Improve the Bounce Rate

Email bounce rate can be reduced using the following methods:

• Use Double Opt-In: A double opt-in campaign is a useful way to gain permission to send out email campaigns. With this method, a contact must respond to an email confirmation to be added to your email address. 

As you’ll not be able to add an invalid email address, you can cut down the bounce rate. 

• Maintain Good List Hygiene: Verify your list daily to remove invalid emails and non-responders. Keeping your list clean is a proven method of achieving higher email delivery rates. 
• Monitor The Email Delivery: You can use online software such as mailproto track your email delivery rates by keeping track of your response rates and bounce rates. With regular monitoring, you can know potential failures before they occur or before they do much damage. 
• Do Not Rent, Buy, Or Harvest Email Address: Buying your email list may get you some quick business, but one can’t rely on the quality of such lists. In such situations, there is a bigger risk of sending emails to invalid addresses and getting blacklisted.  
• Check the Message Against Spam Filters: Content filters block many messages. You can reduce those bounces by identifying the problem and fixing them. 
• Authenticate Your Emails: Another method is to sign emails with Domain Key Identified Mail (DKIM) to ensure credibility and increase email deliverability. To generate DKIM and SPF records, visit “Service Settings” and choose “Email Authentication.”

How Bounce Rate Affects Deliverability?

• Blacklisting: Frequently observed bounce rates send the sender's IP address to be on blacklists supported by ISPs and anti-spam organizations.
• Lost money: Since email service providers are charging you for each message you send, Invalid email addresses increase the cost of your email campaigns without any ROI.
• Low inbox placement: Mailbox providers track bounce rates for each campaign you send and use this information to decide where to send your emails in the future. And many mailbox providers are known to block the sender's email domain for repeated sending to email addresses from non-existent domains.
• Bad reputation: The mailbox provider watches and monitors the IP addresses that continuously send messages to invalid users. They even adjust the sender's reputation accordingly.
• Suspended accounts: Email service providers have a strict policy regarding complaints and bounce rates. They will immediately suspend the user's account if the campaign sent by the user causes a complaint rate that exceeds the limit authorized by the ESP. They do this because high bounce rates can blacklist their sending IP addresses and potentially affect other users of their service.

How to fix the email bounce?

Make sure you have the correct email address. Pay attention to simple typos, extra spaces, or @ symbols.

If temporarily unsuccessful, wait and send a follow-up email. Your mail server should resend the message automatically.

If you have a hard bounce error 550, you need to contact your email service provider. Your email administrator or provider can review your bounce and fix the error.

If you provide the email headers for your bounce, your email administrator can usually quickly detect the problem. If you're blacklisted, you can check out software Mailpro.

How to Check Email Bounce Rate?

After you’ve sent an email to the recipients, you must monitor the results to see which areas need improvement. Mailpro email service software allows the monitoring of general statistics for email campaigns. Once you send the emails to your contacts, this software will start tracking statistics and analyze the email delivery rate and reactivity of your email campaigns.

Mailpro keeps the bounce rate as low as possible so you can deliver as many emails as you want. Along with monitoring the email acceptance rates of the outgoing IP address, we use algorithms to adjust sending rates and which IPs are used.    

Why Mailpro?

With Mailpro, you can find an accurate and complete summary of all your campaigns. These numbers show the results of the behavior of all your campaigns in real-time. The software allows you to easily study and understand the behavior of your current as well as past campaigns.

With Mailpro, you can even see and calculate the results, which will reveal where you have lacked and how you can improve the bounce rates.

Additionally, the software gives you the detail of your campaigns with graphs, which summarizes the email delivery rate and reactivity of your email campaigns. If you want more detailed statistics visualization, we have various plans for you. Check them out now.

Along with campaign statistics and reporting,MMailpro can also help you with contact management, email automation, email marketing campaign, SMS campaigns, SMTP relay server, deliverability and routing, and more.     

Final Words

Bounce rates are directly associated with the quality of your subscriber list. For a healthy, permission-based list having active subscribers, you need to have a low bounce rate. High bounce rates are a result of how badly you managed your list or how you grew the list.        

The healthy email list should see bounce rates of between 2-3%. So, if you’re regularly getting higher bounce rates, you need to identify the problem and take immediate action to control the bounce rate.

Mailpro can help you investigate the reason of increased bounce rates and work out how to fix the issues, so please do give us a call. If your bounce rates are continuously growing, it may lead to suspension of your account. To avoid the case, you should start using the email marketing software available online.