Cisco Cisco Web Security Appliance S690 User Guide
25-16
Cisco IronPort AsyncOS 7.7 for Web User Guide
Chapter 25 Configuring Network Settings
Configuring SMTP Relay Hosts
Configuring SMTP Relay Hosts
AsyncOS periodically sends system-generated email messages, such as notifications, alerts, and Cisco
IronPort Customer Support requests. By default, AsyncOS uses information listed in the MX record on
your domain to send email. However, if the appliance cannot directly reach the mail servers listed in the
MX record, you must configure at least one SMTP relay host on the appliance.
IronPort Customer Support requests. By default, AsyncOS uses information listed in the MX record on
your domain to send email. However, if the appliance cannot directly reach the mail servers listed in the
MX record, you must configure at least one SMTP relay host on the appliance.
You might want to configure an SMTP relay host in the following scenarios:
•
You want the system-generated emails to go to a non-local email address, and port 25 is blocked to
outside networks.
outside networks.
•
Your mail servers do not allow direct port 25 traffic from internal hosts.
If no SMTP relay host is defined, AsyncOS delivers directly to the mail server for each email address.
Note
If the Web Security appliance cannot communicate with the mail servers listed in the MX record or any
of the configured SMTP relay hosts, it cannot send email messages and it writes a message in the log
files.
of the configured SMTP relay hosts, it cannot send email messages and it writes a message in the log
files.
You can configure one or more SMTP relay hosts. You might want to configure multiple SMTP relay
hosts for redundancy in case one system becomes unavailable. When you configure multiple SMTP relay
hosts, AsyncOS uses the topmost available SMTP relay host. If an SMTP relay host is unavailable, it
tries to use the one below it in the list.
hosts for redundancy in case one system becomes unavailable. When you configure multiple SMTP relay
hosts, AsyncOS uses the topmost available SMTP relay host. If an SMTP relay host is unavailable, it
tries to use the one below it in the list.
You can configure the SMTP relay host from either the web interface or command line interface:
•
Web interface. Use the Network > Internal SMTP Relay page.
•
Command line interface. Use the
smtprelay
CLI command.
Configuring SMTP from the Web Interface
Step 1
Navigate to the Network > Internal SMTP Relay page.
Step 2
Click Edit Settings.
Step 3
Enter the information listed in
Step 4
Optionally, you can add more SMTP relay host information by clicking Add Row.
Table 25-4
SMTP Relay Host Settings
Property
Description
Relay Hostname or IP
Address
Address
Enter the hostname or IP address to use for the SMTP relay
Port
Enter the port for connecting to the SMTP relay. If this property is empty, the
appliance uses port 25. This property is optional.
appliance uses port 25. This property is optional.
Routing Table to Use
for SMTP
for SMTP
Choose the routing table associated with an appliance network interface,
either Management or Data, to use for connecting to the SMTP relay. Choose
whichever interface is on the same network as the relay system.
either Management or Data, to use for connecting to the SMTP relay. Choose
whichever interface is on the same network as the relay system.