Hi, Everyone: We have a fairly large mailing list running on IRIX Listserv 1.8c. The mail has been forwarded to LSMTP running on NT 4.0 by specify SMTP_FORWARD="my.lsmtp.node" in go.user file. Last night we send out our weekly delivery and this morning we got people from two domains complain they've getting multiple copies of the mail. This only happened to people from these two domains and no one else. Emails to these two domains have no problem at all last week. I check into the logs for LSMTP and Listserv and the mail has been delivered just once. I contact both domain mail administrators. One administor look into their mail server and only found one delivery come into their firewall last night (for a particular user that complaint). However the mail will be sent to a Lotus Notes mail for internal delivery. The other one look into the log and see a lot of duplicates comming in. They own their own domain and connect directly to SprintLink. Apparent there is no ISP in the middle. It look like the problem is at destination end, not our end. Does any one have any idea what had happened here? Any suggestions to handle this kind of problem, both from technical trouble shooting point of view as well what to tell your customer when it happened? Thanks a lot George Tsai