“Here, even if the smudge in the signature line could be considered a ‘signature’ by an individual, no evidence in the record exists to show where the certified mail was actually delivered, because the return receipt does not contain a specific address as required by Civ. R. 4.1(A)(1),” the court said. “In this case, the illegible smudges on the signature line and on the address line in the certified mail return receipt, along with the uncontested affidavits from REST’s officer, employee, and agent averring that REST did not receive the summons and complaint are sufficient to establish that service on REST was not proper.”