N.M. Stat. § 39-5-15
In all actions brought for the foreclosure of any real estate mortgage or deed of trust where the plaintiff alleges in his complaint that any person who is now deceased, during his lifetime, claimed a lien upon the real estate described in said mortgage or trust deed and further alleges either that there has been no administration of such decedent's estate, or that the plaintiff is unable to ascertain the names, residences and whereabouts of the heirs, devisees or legatees of such deceased person he may make such unknown heirs, legatees and devisees of any such deceased person parties defendant to said cause under the name, style and designation of "unknown heirs, devisees, or legatees, of (here insert name of deceased person), deceased"; and service of process on and notice of said suit against such defendants shall be made as provided by law and the rules of court.
NMS § 39-5-15