If u have already SMTP connector….
1. Open Exchange System Manager and click on the + next to Connector
2. Right-click > Properties
3. General tab > provide name for identifying
4. Select “Forward All Mail Through This Connector To The Following Smart Hosts”,
5. Now provide an IP address of other site mail server and must enclose with brackets
6. Under Local Bridgeheads > Add > select SMTP server
7. On Address Space tab > Add > SMTP > OK
8. In E-Mail Domain box, u may add name of remote location’s e-mail domain & click OK
9. On Advanced tab > select Outbound Security > select proper authentication method
10. Click OK thrice and exit
Now restart exchange routing engine service and the SMTP service
Hope it may help u !