How does auto-delete work?
ListProc will auto-delete and auto-postpone subscribers as long as the AUTO-DELETE option is set for the list. The decisions as to which action to take are based on error mail (usually sent to “owner-listname”, since this is automatically placed in the Sender field of outgoing list mail) account by the MTA (Mail Transport Agent, i.e… mail server program). Most likely, your local MTA is set up to send warning messages back to the sender if a message was not able to go out for a specified amount of time. (5 hours is a common number.) ListProc then sees this warning message, interprets it as an intermittent error, and sets the subscriber’s mail method to “postpone.” User unknown or host unknown type errors usually result in deletion. If a number of people end up being deleted/postponed as a result of this, you might want to turn off auto-deletion for the list. For large lists, however, this is probably not a good idea, as it creates a lot of extra work for the owner to remove bad addres
