Miss. Code Ann. § 13-3-25: Miss. Code Ann. § 13-3-25

When unknown heirs are made parties defendant in any proceeding in the chancery court, upon affidavit that the names of such heirs are unknown, the complainant may have publication of summons for them and such proceedings shall be had thereupon in all respects as are authorized in the case of a nonresident defendant. When the parties in interest are unknown, and affidavit of that fact be filed, they may be made parties by publication to them as unknown parties in interest.