Secure Computing SG300 User Manual page 149

Select E-Mail from Services.
Enter your internal email server's IP address in To Destination Address.
Click Finish.
Configure mail clients on the Internet with the SG unit's Internet IP address as the server
to use for sending (SMTP) and receiving (POP3 or IMAP) mail. If your SG unit has a
dynamic Internet IP address, consider using a dynamic DNS server; see Dynamic DNS in
the DNS section of the chapter entitled Network Setup.
Source NAT
Source NAT alters the source address of packets received by the SG unit. This is
typically used for fine tuning the SG unit's masquerading behaviour.
See the Masquerading section later in this chapter for information on altering the basic
masquerading relationships between your SG unit's interfaces.
Click Source NAT. Any rules that have already been defined are displayed, you may
Edit or Disable/Enable these rules by clicking the appropriate icon. Click New to add a
new rule.
You may also add a new rule above an existing one by clicking the Add Above icon, or
below with Add Below.
Note
The first matching rule determines the action for the network traffic, so the order of the
rules is important. You can use the Move Up and Move Down icons to change the order.
The rules are evaluated top to bottom as displayed on screen.
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Firewall