25 Del. C. § 81-127: Notice.

(a) Unless otherwise required or permitted by the declaration or bylaws, the following methods of giving notice suffice when notice is required:

(i) Hand delivered to the unit owner or other intended recipient;

(ii) Sent prepaid by United States mail to the mailing address of each unit or other intended recipient, unless that person has designated in writing a different mailing address in which case it shall be sent to the designated address; or

(iii) Sent by electronic means in the manner described in subsection (b) of this section.

(b) An association provides effective notice by electronic means if the unit owner gives the association prior written authorization to provide that notice, together with an electronic address.

(c) The ineffectiveness of a good faith effort to deliver notice by any authorized means does not invalidate action taken at a meeting or in lieu of a meeting.