CLOUD SOLUTIONS

Queue retention and retry times

Email Security has a set of policies which determine how long an undelivered message will be kept in the email queue. The period that a message is kept depends on the reason why the message failed to deliver:

  • A 5xx error message was returned - the connection resulted in a permanent failure. The email will be deleted and no attempt will be made to retry this message.

  • A 4xx error message was returned - Persistent transient failure. Persistence of some temporary condition has caused abandonment or delay of attempts to send the message. Sending the message will be retried until the time passed since the email was sent is greater than the retention policy.

  • A connection cannot be made. Sending the message will be retried until the time passed since the email was sent is greater than the retention policy.

Note

These policies are created in accordance with the official RFC standards.

Retention times

  • For outbound mail, the retention time is 4 hours. If the retention period does expire before successful delivery or the remote server replies with a 5xx error code a NDR is sent back to the sender.

  • For inbound mail, the retention time is set to 6 days. No NDR (Non-delivery Receipt) is not sent back to the remote sender on inbound emails.

Retry times

If the first attempt to deliver an email fails, the delivery will be retried for a specific amount of time. This is called a retry interval.

For Email Security the retry interval is 30 minutes for both inbound and outbound emails. If multiple routes exist for inbound email, each route is tried, and if all fail, the email is retried 30 minutes later.

Note

To change these values please contact your Service Provider.