> On of my list owners is being plagued with "was delivered" error messages.
> He has gotten at least some 20+ errors. He can't tell exactly who from or
> who to or who by; the subject line to him keeps changing, the one below is:
> ATKINS-NEW: error report from PROTRADER.COM. Did someone post a message
> that asked for an acknowledgement that it was read? How could Listserv let
> such go through? Don.

The sample message you sent is a delivery receipt from Microsoft
Exchange.  I've seen the same effect (lots of delivery receipts
from different addresses).  I believe it is caused by an Exchange
user requesting a delivery receipt for a message sent to the list.
The request is buried in the base64 encoded MS-TNEF file, which
LISTSERV does not understand.

You may be able to identify the culprit by looking for the original
message with the subject mentioned in the delivery receipts.