I Can't seem to figure this out, i have SD Plus set up through exchange 07, it will send mail to local users with no problems at all, but when it send out to users with an external email address (IE: hotmail) i get that message in the logs, and if i post a response on sd to a user with an external email address, it said sending failed right away, it doesnt make sense. and sd has a domain account to use to login to the exchange to send mail.