ZyXEL UAG715 User Guide - Page 206

Chapter 17 SMTP Redirect server. The older POP2 requires SMTP for sending messages while the newer POP3 can be used with or without it. This is why many e-mail applications require you to specify both the SMTP server and the POP or IMAP server (even though they may actually be the same server). SMTP Redirect, Firewall and Policy Route With SMTP redirect, the relevant packet flow for SMTP traffic is: 1 Firewall 2 SMTP Redirect 3 Policy Route Even if you set a policy route to the same incoming interface and service as a SMTP redirect rule, the UAG checks the SMTP redirect rules first and forwards SMTP traffic to a SMTP server if matched. You need to make sure there is no firewall rule(s) blocking the SMTP traffic from the client to the SMTP server. You also need to manually configure a policy route to forward the SMTP traffic from the SMTP server to the Internet. To make the example in Figure 130 on page 205 work, make sure you have the following settings. For SMTP traffic between lan1 and dmz: • a from LAN1 to DMZ firewall rule (default) to allow SMTP messages from lan1 to dmz. • a SMTP redirect rule to forward SMTP traffic from lan1 to SMTP server A. For SMTP traffic between dmz and wan1: • a from DMZ to WAN firewall rule (default) to allow SMTP messages from dmz to wan1. • a policy route to forward SMTP messages from SMTP server A to the Internet. 17.2 The SMTP Redirect Screen To configure redirection of a SMTP message to a SMTP server, click Configuration > Network > SMTP Redirect. This screen displays the summary of the SMTP redirect rules. Note: You can configure up to one SMTP redirect rule for each (incoming) interface. 206 UAG715 User's Guide