Service upon the sheriff of a paper other than process may be made by delivering it or a copy thereof to the sheriff or to one of the sheriff’s deputies or to a person in charge of the sheriff’s office during office hours, or, if no such person is there, by leaving it in a conspicuous place in the office. When any process remains with the sheriff unexecuted, in whole or in part, at the time of the sheriff’s death, resignation of office or at the expiration of the sheriff’s office such process shall be executed by the sheriff’s successor in office; and when the sheriff sells real estate under and by virtue of an execution or order of court the sheriff or the sheriff’s successor in office shall execute and deliver to the purchaser all such deeds and conveyances as are required by law and necessary for that purpose, and such deeds and conveyances shall be as valid in law as if they had been executed by the sheriff who made the sale.