Understanding and managing email bounce on systeme.io

The purpose of this article is to clearly define the concept of an email bounce, a critical metric for deliverability.

We will explain the mechanisms behind bounces, as well as the distinction between “hard” bounces (permanent delivery failures) and “soft” bounces (temporary failures), and their impact on sender reputation.

1. What is an email bounce?

An email bounce occurs when an email is not delivered to an email address. In such cases, the sender can often view which contacts didn’t receive the message, either in the email statistics or in each contact’s email history. This failure comes from the recipient’s mail server for various reasons.

The reasons for a bounce can vary. In some cases, the email address is invalid or no longer exists, often due to a typing error or an old contact base. In other situations, it may be a temporary problem, such as a full inbox or an unavailable server. It also happens that anti-spam filters on the recipient's side block the receipt of the message.

A high bounce rate is an important indicator of a list quality problem. Indeed, it often reflects an outdated, poorly maintained, or insufficiently verified contact base. Mail providers like Gmail or Outlook closely monitor this type of signal to evaluate sender reliability. If you frequently send emails to invalid addresses, you are progressively considered a risky sender.

This damage to your reputation has direct consequences: your emails are more likely to be redirected to the spam folder, or even completely blocked before reaching the recipients. This is why it is essential to monitor bounces and maintain a clean and up-to-date contact base, in order to preserve good deliverability and ensure that your campaigns actually reach their audience.

2. Categories of bounces

On Systeme.io, there are two categories of bounces you may encounter: soft bounces/blocks and hard bounces.

Soft bounces should be considered temporary blocks; it is not necessary to permanently remove the email addresses that did not receive an email from your contact list.

On the other hand, hard bounces refer to permanent delivery failures. This means the email address is invalid, non-existent, or permanently unavailable. In this case, it is essential to immediately remove these addresses from your contact list, as continuing to send them emails directly harms your sender reputation.

You can easily identify them in your statistics. When an address appears in gray, it indicates a hard bounce (1); the email could not be delivered and never will be.

Conversely, an address displayed in blue and clickable corresponds to a soft bounce (2), meaning a temporary failure (unavailable server, etc.).

These addresses in blue remain active in your contact list, as it is possible that the delivery will work during a future sending and their contact record is still available.

a. Soft bounce:

A soft bounce means the recipient's email address is valid, and the message reached the recipient's mail server, but it was rejected before being delivered to the inbox.

Systeme.io does not mark the contact as “bounced” in your contact list since the rejection only applied to that specific message.

Common reasons for a soft bounce include:

• The recipient's server is temporarily unavailable
• SMTP server not responding
• Blocked IP address
• Blocked domain (blacklisted)
• Content or links flagged as suspicious or spam

b. Hard bounce:

• The email address is invalid
• The email address does not exist
• The recipient’s inbox is full

1. Bounced status in the contact list: If the recipient’s inbox is full, the email address is marked as “bounced” in your list. Any future emails to this contact won’t even be attempted; we know the message won’t be delivered, so we prevent it from being sent. Continuing to send to bad addresses harms your deliverability.

Note: As a systeme.io support member, we can manually reactivate a bounced contact, but only if you're sure the email address is now valid or available.

2. Fake or non-existent addresses: These addresses are automatically removed from your contact list once identified as fake or deactivated.

3. How to improve your email bounce rate

Reducing your email bounce rate is essential to ensure your messages reach your audience and generate positive engagement. Here are some tips:

• Regularly clean your email lists: Remove invalid, inactive, or unengaged addresses to maintain list quality and reduce bounces.
• Use double opt-in forms: Ask subscribers to confirm their subscription through a link sent by email. This ensures only real, interested subscribers join your list, and it reduces the chance of bounces.
• Add reCAPTCHA to your forms: This prevents bots from subscribing and adding bad contacts to your list, especially useful even if you already use double opt-in.
• Personalize your emails: Use subscriber data (interests, past behavior, purchase history) to create tailored content. Personalized emails tend to get more opens and clicks, which improves engagement and reduces bounces.
• Send emails consistently: If you haven’t contacted your list in a while, some addresses may no longer exist, resulting in hard bounces. Also, if you rarely email your list (or haven’t cleaned it recently), your contacts may forget you and mark your emails as spam.
• Segment your list: Divide your list based on criteria like location, preferences, or behavior. Sending more relevant content to each segment can reduce bounces.
• Use email verification tools: Before sending, check your list with verification tools to detect and remove invalid or inactive emails.
• Avoid spam-like words and practices: Don’t use excessive capitalization, exaggerated claims, or overly frequent sending, as these can trigger spam filters.
• Encourage engagement and replies: Include clear, relevant calls to action in your emails to invite clicks, replies, and interaction. Engaged subscribers help boost your sender reputation and reduce bounce rates.

By following these tips and monitoring your email performance metrics closely, you will be able to significantly lower your bounce rate. This not only helps you to maintain a clean and reliable contact list but also improves deliverability and the overall effectiveness of your emails, ensuring that your messages actually reach your recipients.