Hi Im setting up Exchange 2007 in my environment for the purpose of only to send emails from applications such as HP Data Protector etcand forward these emails to external email addresses via an external Exchange Server. The environment where the applications and the Exchange server resides is secured andlocked down for allcommunication to external environments butonly certain applicationportsareopened. This being the case,I also need to find out what network portsare required for this communication to another external Exchange Server 2003or 2007. Im quiet new to Exchange 2007 and not sure on how to go about this. Please advice. Cheers

Hi, if i understand your problem correctly what you need is to send an email to an user in the exchange organization and that email be forwarded to an external domain, to do this you need to create a contact in the active directory and on the users exchange general tab forward the email to that contact. For communicating to diferent exchange organizations only smtp (and proper DNS resolution) is necessary just like any other email system. If you dont want to create contacts on your ad you can give relay permissions on the SMTP virtual server for your application (like Data protector) and configure directly the external email addresses on this application hope it helps, Pablo