Persons making an enrollment under this chapter shall, at the time of making same, serve a notice of such enrollment upon each person enrolled, by delivering such notice to the enrollee personally or by leaving it with some person of suitable age and discretion at his or her place of business or residence, or by mailing such notice to him or her at the enrollee's last known place of residence, and shall make a return under oath of such service to accompany the copy of the enrollment filed with the adjutant general. The return shall be prima facie evidence of the facts therein.