'X-Priority' field (Outlook specific). Value ranges from "1" to "5" where "1" is the highest priority, "3" is normal, and "5" is the lowest priority. It's easier to use PriorityHigh()()()() or PriorityLow()()()() methods then setting this field.

public Nullable<int> XPriority { get; set; }

Public Property XPriority As Nullable(Of Integer)
	Get
	Set

public:
property Nullable<int> XPriority {
	Nullable<int> get ();
	void set (Nullable<int> value);
}