When an email bounce occurs, the details are stored in the Events table. Temporary failures are retried every 15 minutes until successful delivery or until the message expiration occurs and a bounced entry is logged on the Events table. In some instances, this retry may be delayed if ROI's automated processes detect a deliverability issue where continued retry is unlikely to result in a delivery. In the majority of cases, these retry rates will not contribute to deliverability issues, and we also attempt to reduce the retry rate if the error message indicates that the bounce was related to a rate-limiting issue.
The ROI platform classifies bounces into the two following categories based on the response from the remote server:
- Transient Failures- These are instances where the receiving server may have a temporary error, or the recipient's mailbox is temporarily unavailable. These may also include situations where a mailbox provider, such as Yahoo!, rejects a message due to rate-limits being exceeded. For transient failures, messages are re-tried at regular intervals for up to 24 hours before being reported as a bounce back in the Events table.
- Permanent Failures- These are bounces where the receiving server returns a response indicating that the recipient is invalid, the mailbox is unavailable and not considered to be recoverable for the message, or where the content of the message is rejected. These bounces are not retried and are reported immediately as bounces on the Events table for the send.
Below you will find the entire list of bounce codes, the categorization of the codes and what action (if any) the system takes when the bounce is received. For more information on Message Gear's bounce handling information, please view their article here.
Contact email@example.com with additional questions.