Importance Property

       

Returns or sets an OlImportance constant indicating the relative importance level for the Outlook item. This property corresponds to the MAPI property PR_IMPORTANCE. Read/write.

OlImportance can be one of these OlImportance constants.
olImportanceHigh
olImportanceLow
olImportanceNormal
 

expression.Importance

expression    Required. An expression that returns one of the objects in the Applies To list.