In case the e-mail could not be delivered on your mail server(s), SpamExperts will retry it according to the standards. The following scheme is used for this:
- During the first 2 hours, every 15 minute the delivery is retried
- The next 14 hours, this interval is increased with a factor of 1.5 (15 minutes, 22½ minutes, 34 minutes, ...)
- Then, delivery will be retried every 6 hours
- If after 4 days the e-mail could not be delivered, the sender will be informed
If your mailserver has a short downtime, most messages will be received within 15 minutes. When the server has a longer downtime, delivery can be delayed some longer. E-mail only permanently bounces if the receiving mailserver is not available for 4 days.
You can see in the Delivery queue in the SpamExperts control panel which e-mails have not yet been delivered, and for what reason.