Indicates whether or not this is the Contact's preferred mailing address (address at which he/she/it wishes to receive mail). NOTE: PreferredMail can only be set to true. When one is set to true, all others are set to false.

public bool IsPreferredMail { get; set; }

Public Property IsPreferredMail As Boolean

public:
property bool IsPreferredMail {
	bool get ();
	void set (bool value);
}