Using procmail with cyrus and postfix in Panther?

Hi guys I follow through the article about the procmail with cyrus and postfix (Dated 13 Nov, 2003) Link: https://www.afp548.com/Articles/Panther/procmail.html. It seems like the procmail is working. But when I included an auto-reply receipt in one of the user's home directory. The mail was auto-replied as user cyrus? Does anyone have this kind of problem? Thanks a lot guys! David