D-Link NetDefendOS User Manual page 93

Multiple events are collected together into each email sent. The number of events collected
before email sending is controlled by the values of the Event count threshold and Event count
period properties.
• Event count threshold
An email is only sent if this number of events has occurred over the preceding number of
minutes specified by the Event count period property. The trigger is therefore a given rate of
events and not just an accumulation of events. Events that have already been included in a
sent email are not counted again.
When a Mail Alerting object is first created, this count is zero and is always reset to zero when
NetDefendOS restarts. When an email is sent by the Mail Alerting, object, this count is also
reset to zero.
This property and the property Event count period are not used if Single event trigger is
selected.
• Event count period
This is the number of minutes referred to in the Event count threshold description above and
is the period of recent time in which events are being counted.
• Send report emails
When enabled, an email is always sent at least in the period of time specified by the Report
email interval, even if the sent email has no events in it and even if the email is has no events
in it or even if (in the case of the Rate of events trigger) the Event count threshold value has not
been reached.
This is not used in Single event trigger mode
• Report email interval
This is the maximum length of time in hours that can elapse before an email is sent even
though the email might contain no events. Typically, this value might be set to 24 so that the
Mail Alerting object generates at least one email a day even though it might be empty. This
can inform the administrator that the system is up and highlight any events of interest.
• Report email subject
When a report email is sent, this will be the subject line of the email. This allows the
administrator to easily distinguish if an email is a report email or an email generated by a
trigger.
The property must have a string value and cannot be left empty.
• Keep collecting before sending
If an email is ready to be sent, NetDefendOS will wait this number of minutes before sending
it. Any new events that occur while the email is waiting to be sent are added to the pending
email.
This can be used in either triggering mode. If the mode is Single event trigger, any new events
during the period after the initial triggering event will be added to the email.
NetDefendOS only sends events in one minute intervals so this means that even is this
property is set to zero, there can still be a delay before the email is sent and extra events can
still be added during this delay.
• Minimum time between emails
Chapter 2: Management and Maintenance
93