25 Del. C. § 5125

(2) A tenant may leave the keys in the rental unit or secured drop box identified by the landlord or leasing office, with written notice to the landlord in reference to where the keys are placed and the date of return. If the landlord provides a secure drop box under this paragraph, the landlord must clearly label the drop box as secured and the tenant’s duty to surrender the keys is completed once the keys are deposited in the secured drop box.85 Del. Laws, c. 295,
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