What is a Bounced Email?

What is email bounce rate?

Email bounce rate is a metric that measures the percentage of emails that were sent but failed to reach the recipient’s inbox. It is not only a delivery metric, but a window into your sender reputation, campaign performance, and how well your business is communicating with their customers. 

Why bounced emails matter

So why does it matter if an email bounces? Understanding why emails bounce is important for anyone managing email campaigns or communication. Bounced emails aren’t just undelivered messages; they can also provide valuable insights into your email strategy’s effectiveness and health. 

Let’s dive into three key reasons why you should pay attention to bounced emails:

1. Cleaning up email lists: When an email bounces because of an invalid address, it’s a wake-up call to tidy up your mailing list. Regularly encountering bounced emails due to incorrect addresses suggests it’s time to verify and update your contacts. This cleanup effort improves your mailing list’s accuracy and enhances your email campaigns’ effectiveness.
2. Improving email deliverability: High bounce rates often point to potential deliverability problems. It could mean your emails are flagged as spam, indicating a need to reevaluate your email content and strategies. Addressing these issues boosts your chances of successfully landing in recipients’ inboxes rather than being sidelined to the spam folder.
3. Monitoring email service performance: A spike in bounced emails can be a red flag about your email service provider (ESP) or the performance of your current email solution. This increase might stem from technical issues, server outages, or policy changes with your ESP. Keeping an eye on bounce rates helps you quickly identify and address these problems, ensuring consistent and reliable email delivery, a cornerstone of effective digital communication.

Bounced email impact on business apps

Bounced emails can significantly impact business applications, influencing everything from customer relationships to revenue. Here are a few examples: 

• Customer engagement and retention: Businesses miss critical opportunities to engage with their customers when emails bounce. Whether it’s a promotional offer, a follow-up, or a newsletter, undelivered emails lose customer touchpoints. This lack of communication can lead to decreased customer engagement and customer attrition. Maintaining consistent and reliable email delivery is crucial for keeping customers informed, interested, and loyal to the brand.
• Revenue loss: Email marketing and sales communications via email drive revenue. Bounced emails, however, signify missed opportunities in converting prospects into customers or upselling to existing clients. Each undelivered email could have been the one that clinched a sale, so a high bounce rate can directly correlate to lost revenue. 
• Reputation and deliverability impact: Frequent email bounces can damage a business’s sender reputation, making it harder for future emails to get through. Email service providers often use sender reputation to determine if an email should land in the inbox or the spam folder. A tarnished reputation due to high bounce rates can lead to even legitimate emails being marked as spam, further reducing the effectiveness of email communication and impacting the business’s ability to reach its audience.

No matter what we did, all outgoing emails ended up in spam folders. A few bad apples spoil the bunch. We tried various solutions to address the problem, including spending $20,000-30,000 on outside consultants, filtering, spam scoring – nothing worked. Nylas solved the email deliverability problem perfectly for us. Our users could send marketing emails through their individualized email accounts rather than with transactional email service providers. Keeping accounts separate has been a big win.

Justin Belobaba

Founder and CEO, Nowsite

Bounce email mechanics: how they work

Navigating the technicalities of bounced emails involves understanding several components, from email delivery to handling bounced messages. 

Let’s break down these elements for a clearer picture:

Types of bounced emails: soft vs. hard bounce

There are two main types of bounces: hard and soft. Recognizing these types of bounces helps senders maintain healthy email lists and improve the chances of successful delivery in future campaigns.

• Hard bounces are the dead-ends of email delivery, often caused by invalid addresses or a domain that no longer exists. Think of them as sending mail to a demolished building. 
• On the other hand, soft bounces are temporary issues, like sending a package to a house where the mailbox is currently full. These emails might get through once the issue is resolved, like if the recipient clears space in their inbox.
  

If you’re looking for a deeper dive into the nuances of email deliverability, specifically related to soft and hard bounces, check out our comparison of the differences between hard and soft email bounces.

Types of Reply codes and what they mean

Each bounced email has a specific reply code. For hard bounces, common codes include:

• 550 (address unavailable) or 551 (user not local).
• Soft bounces might have codes like 451 (temporary local problem) or 452 (insufficient system storage).

These codes help in identifying the exact nature of the bounce.

Understanding bounce message content

To gain a better understanding of why an email has bounced, look at the bounce message content. The bounce email contains detailed information about why the email wasn’t delivered. This might include the reason for the bounce, the original email’s header, and sometimes a part of the email body for context. It will look something like this: 

Subject: Undelivered Mail Returned to Sender

Body:

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed permanently:

* [email protected]

Reason for failure: Address not found - The email account you tried to reach does not exist.

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain example.com by smtp.example.com. [192.0.2.123].

----- Original Message Header -----
From: [email protected]
To: [email protected]
Sent: Thursday, March 31, 2023, at 10:15 AM
Subject: New Product Launch

----- Part of the Message for Context -----
Hi there,

I'm excited to introduce our latest product...

[Message truncated]

Understanding why an email has bounced is the first step to analyzing and handling bounced messages.

Handling bounced messages

Effective management of bounced emails involves analyzing the bounce message content and reply codes. For hard bounces, it’s usually best to remove the email addresses from your list. For soft bounces, you might retry sending the email after some time or investigate the cause.

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Top 3 bounce email challenges & best practices

While bounced emails provide insights and opportunities for improvement, they also bring distinct challenges that require strategic management. For developers managing email systems and integrations, implementing best practices for handling bounced emails is crucial. Here are three common challenges and essential best practices to address them:

Challenge 1: Resource allocation and time management

Effectively handling bounced emails demands significant time and resources. For businesses, especially those with large mailing lists, sorting through and addressing each bounced email can be time-consuming. This process involves removing invalid addresses and analyzing the causes of bounces, which requires a dedicated effort. Allocating the right resources to this task is essential for maintaining an efficient communication strategy without diverting excessive attention from other critical business operations.

Best Practice 1: Implement real-time email validation

Integrate real-time email validation in your sign-up processes. This proactive approach checks the validity of email addresses as they are entered, reducing the likelihood of hard bounces due to invalid addresses.

Challenge 2: Data analysis and strategy adjustment

Bounced emails generate a wealth of data that needs careful analysis. Understanding the patterns in bounce rates, such as specific times when bounces increase or identifying particular campaigns with higher bounce rates, is crucial. This analysis must then inform strategy adjustments, whether tweaking email content, timing, or frequency. Making informed decisions based on bounce data is key to enhancing overall email campaign effectiveness.

Best Practice 2: Monitor and Analyze Bounce Patterns

Regularly monitor and analyze the patterns in your email bounces. This analysis helps identify email campaign or delivery system issues, allowing for timely interventions and strategy adjustments.

Challenge 3: Adapting to new email security standards 

Another challenge for businesses is adapting to new email security standards set by major providers like Google and Yahoo. For instance, starting in 2024, Gmail will require bulk senders to authenticate their emails, allow easy unsubscription, and maintain a low spam report rate. Non-compliance with these standards could lead to increased email bounces, as the recipient’s server may reject emails failing to meet these criteria. Adapting to these changes is essential to ensure emails are successfully delivered and not bounced due to heightened security measures.

Best Practice 3: Automate bounce management

Develop an automated system for managing bounces. This includes categorizing bounces as hard or soft, updating email lists accordingly, and automating responses or re-sending strategies based on the type of bounce.

Adhering to these practices helps ensure effective email delivery, maintain a clean email list, and preserve a good sender reputation.

Minimize bounced emails with Nylas

In managing bounced emails and ensuring email deliverability, the Nylas Email API is a powerful tool, helping users tackle challenges like maintaining accurate email lists and keeping up with various ESP changes. Nylas also enhances email deliverability by allowing direct email sending from individual addresses, reducing the likelihood of emails being marked as spam. Additionally, our APIs provide analytics and support email threading, ensuring reliable and effective email communication for businesses.

For more information on how Nylas can help your business avoid bounced emails and ensure near-perfect email delivery, connect with a platform specialist.