One of the roles an owner has, is to deal with error messages that might result from messages sent to a group and which are not handled by the LISTSERV© Auto-Delete mechanism (see below).
Typically, these errors result from subscribers whose email addresses no longer exist, but who have forgotten to remove themselves from the group. These are called 'delivery errors' or 'bounces'. The remote mail server will normally return the original email along with a message to say why it could not be delivered.
When you receive an error message of any sort you need to identify what it is. Most delivery errors, will contain phrases like 'No such user' or 'Recipient address not recognised' and quote the email address that failed. In this case, you can remove the subscriber from your group. However, if the error says something like 'Mailbox full', it is not a permanent problem and can be ignored.
LISTSERV provides a mechanism to automatically delete subscribers whose email addresses are no longer valid, or where there are lasting problems with their mail system.
It does this is by processing delivery errors; providing such errors are correctly sent by the remote mail system and are in one of the many formats LISTSERV recognises, the auto-delete mechanism will deal with them. If not, they will be sent to the owner and should be handled as described above.
The auto-delete mechanism can be controlled by adjusting the List Configuration. By default, the retry period is 4 days or 100 delivery attempts - this is to allow for temporary problems that a subscriber's mail system may be experiencing. If the delivery fails after the retry period, LISTSERV will delete the subscriber. However, a listowner may opt to have a different retry period, or no Auto-Delete option at all.
Subscribers being monitored by the auto-delete mechanism, will appear on a 'Daily Error Monitoring Report' sent to owners of groups.
Note: It is possible for an address to appear on the monitoring report that isn't subscribed to the group. This is usually caused by a subscriber having their mail forwarded to another account which is reported on the delivery error.
If you receive any errors that you cannot decipher, the Helpline can assist.