This document explains the methods Server Monitor uses to send email notifications. This document applies only to Mac OS X Server versions 10.1.5 to 10.2.8.
Server Monitor consists of two separate pieces of software. The "hwmond" process is the hardware monitoring on the server itself. The Server Monitor application remotely monitors the server via communication with hwmond.
There are two ways to have notifications sent. The server can be configured to send notifications itself. In this case, hwmond just creates a text file and pipes it through sendmail. In order for this to work correctly, make sure the permissions on the root directory ( / ) don't allow group or other write permissions. The permissions for / are set to 1755 when Mac OS X Server is installed. Some software updates modify this, enabling group write permission, which causes sendmail to exit without sending any mail.
The Server Monitor application can also be configured to send email notifications. Note that it is not possible to have both hwmond and Server Monitor send notifications. Choose one or the other. Server Monitor uses the Message.framework to send the notification. The Message.framework looks in two places for a way to send email. The first is that it looks for an SMTP server configured in the Email tab of Internet preferences. The other way is to use an email account configured in Mail. If an outgoing SMTP server is configured in Internet preferences, there is no need to configure the Mail application.