I did think of the time delay, so to make sure this evening I made the changes, restarted the VS and restarted the machine and still no joy! FYI (if it makes a difference) this is a single Server network with Exchange, AD, ISA etc. on 1 server (But not SBS 2000) ...Spence -----Original Message----- From: Mulnick, Al [mailto:Al.Mulnick@xxxxxxxxxx] Sent: 08 December 2003 14:01 To: [ExchangeList] Subject: [exchangelist] RE: Strange unknown recipient question http://www.MSExchange.org/ You're aware there is a latency between checking that box and it taking effect, right? Once you make that change, wait for DS2MB replication and restart the VS and see if you get the same result. Al