A bounce occurs when a sent email cannot be delivered to the targeted recipient. Bounces can be categorized in two types, depending on the cause of the rejection : hard bounces and soft bounces.
Bounce rates are an essential metric in performance tracking, as it reflects the proportion of emails that actually reach their destination and are received by your contacts. They are also valuable indicators when monitoring your deliverability: email service providers use bounces to assess the quality of your emails and sending practices. High bounce rates can harm your sender reputation, leading to automatic placement of your messages in spam folders.
This article will explain the characteristics of each bounce type, and explain how they are processed by Probance One.
1. Soft bounces
A soft bounce is a temporary failure to delivery the email to the recipient. It occurs in the following cases :
- The recipient’s mailbox is full and cannot receive new emails
- The recipient’s mailbox is inactive
- The recipient’s server exists, but does not respond
- The email is too heavy to be delivered
- The email is blocked by the recipient’s server because of its content
Soft bounces therefore identify failed deliveries to valid and potentially reachable email addresses.
While soft bounces are considered less critical than hard bounces in terms of their impact on deliverability, they still need to be monitored as a high soft bounce rate may indicate poor email practices. Over the long term, this can also negatively impact your sender reputation.
2. Hard bounces
A hard bounce is a permanent failure to deliver the email to the recipient. It occurs in the following cases :
- The recipient’s email address is invalid
- The recipient’s domain is invalid
- The recipient’s mailbox has been inactive for an extended period of time
- The recipient’s email address has been blocked by Probance due to multiple successive soft bounces
- The sender email address is blocked by the recipient
Hard bounces therefore identify email addresses that are invalid, blocked or non-existent, and that will never contactable.
A high hard bounce rate can have a significant impact on your future deliverability. It signifies a lack of quality control over your contactable base, which may be interpreted by email services as a sign of poor acquisition methods.
3. Impact on Probance One’s optin
To maintain a quality contact base, and help you uphold your sending reputation, Probance One automatically processes profiles linked to email addresses that have generated bounces.
Thus, an email address become non-contactable when it has recorded 1 hard bounce, or 5 softs bounced since the last open, and the contact becomes non-optin.
Addressing bounces alone is not sufficient to ensure good deliverability. It is necessary to monitor your sending performance and implement preventive measures in case of high bounce rates. We recommend reading this guide, which compiles best practices to optimize your deliverability and provides recommendations to follow: Preserving My Sender Reputation and Deliverability.