Service Forwarding: SMTP Forwarding host for each WAN link
Most dutch consumer ISP's don't allow access to TCP port 25 other then on their own network. When having multiple WAN links the LAN mail server never knows which ISP will be used an to which SMTP host the mail messages should be directed. Therefore when TCP port 25 is accessed over a WAN link, all these connections should be intercepted and forwarded to the specified SMTP host of the corresponding ISP.
Input values for each WAN link:
a. [Enable Forwarding?]
b. [SMTP Server]
c. [SMTP Port]