hi all, i'm using 5.5 sp2 on a 2k server. i've made sure that the server cannot be used to relay mail. unfortunately the server refuses to relay messages it was never meant to relay. let me explain eg the server has the domain add.org.uk. if someone from outside the network emails fred@xxxxxxxxxx and cc it to joe@xxxxxxxx, they will get an ndr from the exchange server for joe@xxxxxxxxx how can i get it to ignore joe@xxxxxxxx and not send out ndr's to originator (or indeed to the system administrator) thanks for your help mark sudron