...
Solution: Notify the list owner this is happening. To do so, contact the list owner(s) and include the error message by emailing <listname-request@listserv.syr.edu>. For example, if the listname is "clocks", send email to <clocks-request@listserv.syr.edu>.
...
Problem Processing Mail
Users of Listserv may send email to a list and receive a return email with the message that an error occurred while processing file 12345678 from somemail@somedomain.com: "Mail has been received for delivery to the XXXXXXXX list from a user that had been served out".
...