A special authorization or variance should not be granted unless prior written notice of at least five days has been mailed by or at the direction of the Town Board, Planning Board or Zoning Board of Appeals, as the case may be, Secretary or Attorney, to each owner of property abutting, or across from, the lands of the proposed land use activity or within 500 feet of the perimeter of the lands. Failure to give or receive such notice shall not invalidate any special authorization or variance granted. The applicant shall be required, as part of the application, to furnish the proper names and addresses of the owners to whom mailed notice is required. Absent such furnishing of names and addresses by the applicant, the Town assessment records may be relied upon.