SMTP Configuration

The SMTP service sends all mail generated by the appliance, typically in response to alerts as configured on the Alerts screen. The SMTP service does not accept external mail; it only sends mail generated automatically by the appliance itself.

By default, the SMTP service uses DNS (MX records) to determine where to send mail. If DNS is not configured for the appliance's domain, or the destination domain for outgoing mail does not have DNS MX records setup properly, the appliance can be configured to forward all mail through an outgoing mail server, commonly called a smarthost.

Table 3-47 SMTP Properties

Property	Description
Send mail through smarthost	If enabled, all mail is sent through the specified outgoing mail server. Otherwise, DNS is used to determine where to send mail for a particular domain.
Smarthost hostname	Outgoing mail server hostname.
Allow customized from address	If enabled, the From address for email is set to the Custom from address property. It might be desirable to customize this if the default From address is being identified as spam, for example.
Custom from address	The From address to use for outbound email.
SMTP Authentication	Defines the Authentication service extension. Options: No Authentication (default; ANONYMOUS in the CLI) Plain
Auth Username	The authorized username if Plain authentication is enabled.
Auth Password	The authorized user's password if Plain authentication is enabled.

When changing properties, you can use Alerts to send a test email to verify that the properties are correct. A common reason for undelivered email is misconfigured DNS, which prevents the appliance from determining which mail server to deliver the mail to. As described previously, a smarthost could be used if DNS cannot be configured.

Table 3-48 SMTP Logs

Log	Description
network-smtp:sendmail	Logs the SMTP service events.
mail	Log of SMTP activity (including mails sent).