Me. Stat. tit. 36 § 557-A
In the case of real property for which no owner is known to the assessors for at least the preceding 20 tax years and for which the assessor has, with reasonable diligence, attempted to determine ownership, the following assessment procedure must be used. [1993, c. 422, §3(AMD).]
Property of an unknown owner is assessed as other property, except that the owner must be indicated as "unknown." Additionally, the assessing must be advertised once a week for 3 consecutive weeks in a newspaper of general circulation in the county in which the property is located. The notice must describe the real estate that is being assessed so that a reasonable person may know, with probable certainty, what premises are subject to tax, together with a statement that the property is assessed to an unknown owner as the result of the failure of a reasonable search to ascertain an owner of record. This newspaper publication is sufficient legal notice of that assessment. At the time of this publication, a copy of the same notice must be sent by certified mail, return receipt requested, to each abutting property owner. [1993, c. 422, §3(AMD).]
If the owner of property is still unknown, after use of this notice procedure for assessment purposes, the tax collector and treasurer shall use the same procedure for those notices required under sections 942 and 943. [1993, c. 422, §3(AMD).]
36 M.R.S. § 557-A