A bounce is encountered when an email fails to deliver to the recipient's email server. This can be a big problem for email marketers, reducing the delivery rate and deteriorating the campaigns' performance.
Bounces happen for many reasons, including wrong email addresses and problems with the recipient's server.
This guide will discuss the different types of bounces and how to check your campaign's bounce rate in Mailmodo's analytics dashboard.
What are hard bounces and soft bounces?
Based on reasons for bounce, bounces can be divided into two categories - hard bounces and soft bounces.
Hard bounce
A hard bounce refers to a permanent issue that prevents an email from being delivered. Issues that lead to hard bounces include:
Invalid or non-existent email address (e.g., e.g., Jonh@gmail.com, instead of John@gmail.com). It may also happen when someone deactivates his/her account, especially due to a job change.
The recipient's email server has completely blocked delivery from the sender server.
When an email hard bounces, it typically indicates that the email will never be successfully delivered to that address in the future. Email servers usually stop attempting delivery for emails that hard bounce to maintain the sender reputation and email deliverability.
Here’s what an email failure notification caused by a hard bounce would look like.
In the context of email bounces, you'll often encounter notifications from "Mailer Daemon." This isn't a real person but rather an automated system used by email servers to send bounce notifications. When your email encounters a delivery issue, the recipient's server will trigger a Mailer Daemon response, informing you of the bounce (hard or soft) and usually providing details about the reason for the failure. These messages offer valuable insights into email deliverability challenges, allowing you to identify and address bounce issues effectively.
Soft bounce
A soft bounce is a temporary failure in the delivery of an email, and you might be able to send an email to the same email address later.
Issues that lead to soft bounces include:
The recipient has temporarily blocked your email address. (4xx error code)
The recipient's mailbox is full.
The email server is facing an overload issue.
The email account has been temporarily disabled.
Incoming email fails to pass SPF authentication.
The email is blocked by recipient’s anti-spam and antivirus.
Try sending emails to these addresses after resolving the errors and check the email delivery rate. If, even after many further attempts, emails are getting bounced, then it's good to put such addresses in your suppression list.
Read how SBNRI managed their suppression list with Mailmodo, leading to a 16% increase in open rates.
Summed up are all the main differences between hard bounces and soft bounces.
| Aspect | Hard Bounce | Soft Bounce |
|---|---|---|
| Failure type | Permanent delivery failure | Temporary delivery failure |
| Error codes | Typically 5xx SMTP error codes (e.g., 550) | Typically 4xx SMTP error codes (e.g., 421, 450) |
| Action required | Remove from list and make no further delivery attempts | Retry delivery after error resolution or later |
| Sender reputation impact | Negative, affects sender credibility | Minimal, if managed promptly |
| Frequency | Usually occurs consistently for the same addresses | May occur for any email address due to temporary issues |
| Failure handling | Emails return to sender once they bounce | Email servers retry delivery before sending it back to sender |
How to know an email has bounced
When an email bounces, the sender typically receives a bounce message. This bounce message informs the sender that the email was not delivered successfully and usually includes details about the reason for the bounce (e.g., invalid recipient’s address, mailbox full, server issue).
Here’s how the sender typically learns that the email has bounced:
Bounce notification: The sender's email server receives a bounce notification from the recipient's email server indicating the delivery failure.
Email analytics dashboard: Many email service providers (ESPs) provide a dashboard where users can view bounce reports. These reports detail which emails bounced, the type of bounce (hard or soft), and the reason.
Where to find email bounce information in Mailmodo?
Mailmodo has an extensive analytics dashboard that gives you insight into the performance of your email marketing campaigns by displaying different email metrics.
Following are the steps to check email bounce information.
Step 1: Log in to your account.
Step 2: Select the campaign you want to track. The analytics dashboard will open.
Step 3: This is a snapshot of Mailmodo's analytics dashboard showing bounces and blocking.
Bounces: The number of contacts who did not receive the campaigns due to non-existent email addresses, recipient's full inbox, or other reasons.
Blocked: The number of contacts that were not sent the campaigns because they unsubscribed or got bounced in the past.
To get in-depth information about the blocked and bounced email addresses, go to User data, and you'll see the following details for all the email addresses you’ve sent the campaign to:
Bounced: True/false
Blocked: True/false
Invalid email address: True/false
Hard bounce: True/false
Blocked reason
Once you have this data, you can fix the issues that are causing the bounce and put these email IDs in the suppression list and stop sending them in the future if needed.
Besides, Mailmodo takes the following actions when the bounce rate surpasses the given limit:
For email bounce rates higher than 3%, we will warn you that your account will be banned from Mailmodo if the rate goes above 5%.
If your bounce rate is higher than 5%, your account will be banned permanently, and you will not be allowed to send any more campaigns using Mailmodo.
Check out our analytics help guide to know in detail.
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Conclusion
Understanding and managing hard and soft bounces is essential for maintaining a healthy email reputation. By diligently categorizing and addressing bounce types, you can significantly improve your email deliverability and overall campaign performance.
Remember, a lower bounce rate means a higher chance of your emails reaching the intended subscriber list, leading to better engagement and ROI. At Mailmodo, we ensure that our clients' bounces are the lowest and that bounce suppression is readily available to improve the campaigns. If you like to learn more about this, please reach out to the Mailmodo team.
