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

To define a severity restriction for the group, set a severity comparison and a UseForSeverity value. For example, to only notify this group 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 group. 

Separate severity rules can be defined for each member of the group; see INotificationGroupMember.UseForSeverityComparison

INotificationAction.Severity,IFileCaptureAction.Severity