For each recipient, you may specify a severity rule to determine whether a given notification message is sent to this recipient. If the message's severity satisfies the criterion for the recipient, it is sent to the recipient; otherwise it is not. 

To define a severity restriction for the recipient, set a severity comparison and a UseForSeverity value. For example, to only notify this recipient for messages with a severity >=8, set UseForSeverityComparison to compGE and UseForSeverity to 8.

Set the value to compUnspecified to not use a severity rule for this recipient. 

Individual addresses can also define their own severity rules.

INotificationAction.Severity,IFileCaptureAction.Severity