Route Emails

I have a home "Vmware" network:

               DC2008, Exchange2010, Win07

                               Internal || (192.168.0.x)

        (10.0.0.x) Perimeter=TMG2010

                              External || (172.16.2.x)

           Local Area Network Edimax (172.16.2.1)

                                            ||

           Wide Area Network Modem (80.x.x.x)

                                              ||

                                I N T E R N E T CLOUD

All i can say is that i cannot send email from my Internal network to the Wide area network and on the contrary. Only internal emails are permitted! Please show me exact tutorial of how to do it.

eternals81