The Delaware Code Title 25 Chapter 51 Section 5113 dictates how various types of official notices are to be delivered to a tenant regarding a residential tenancy:
Service of Notices or Pleadings and Process
(a) Any notice or service of process required by this Code shall be served either personally upon the tenant or landlord or upon the tenant by leaving a copy thereof at the person’s rental unit or usual place of abode with an adult person residing therein; and upon the landlord by leaving a copy thereof at the landlord’s address as set forth in the lease or as otherwise provided by landlord with an adult person residing therein, or with an agent or other person in the employ of the landlord whose responsibility it is to accept such notice. If the landlord is an artificial entity, pursuant to Supreme Court Rule 57, service of the notice or process may be made by leaving a copy thereof at its office or place of business as set forth in the lease with an agent authorized by appointment or by law to receive service of process.
(b) In lieu of personal service or service by copy of the notice or process required by this Code, a copy of such notice or process may be sent by registered or certified mail or first-class mail as evidenced by a certificate of mailing postage-prepaid, addressed to the tenant at the leased premises, or to the landlord at the landlord’s business address as set forth in the lease or as otherwise provided by landlord, or if the landlord is an artificial entity, pursuant to Supreme Court Rule 57, at its office or place of business. The return receipt of the notice, whether signed, refused or unclaimed, sent by registered or certified mail, or the certificate of mailing if sent by first-class mail, shall be held and considered to be prima facie evidence of the service of the notice or process.
(c) In the alternative, service of notice or process may also be obtained by 1 of the following 2 alternatives:
(1) Posting of the notice on the rental unit, when combined with a return receipt or certificate of mailing; or
(2) Personal service by a special process-server appointed by the Court.
Del. Code § 5113
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