Allowing internal (relay) server to send external email with Exchange 2007

Environment:
Exchange 2007 - (2) HUB Servers with NLB


I have an internal web server that is allowed to relay email per my (configured) SMTP Relay Connector.  The IP of the web server is allowed to relay per the properties of the "Inbound SMTP Relay" Connector.  

The web server can send internal, but not external email.  When I try to send external email from the desktop of the server via telnet I get:

550 5.7.1 Unable to relay

I ran the following to allow authenticated users to send email on the Connector, but no change.

Get-ReceiveConnector "Inbound SMTP Relay (NLB)" | add-adpermission -user AU -extendedrights ms-Exch-SMTP-Accept-
Authoritative-Domain-Sender

Do I need to restart the Trasnport Service on the 2007 Hub Server for the change to take effect?  
Am i on the right track here to allow the internal server to send external as well as internal email?

thanks,

jw