While early law drew the line of finality of the legal act for deeds at the stage known technically as "delivery", modern jurisprudence has progressed from such strict formalism to a "liberal and flexible practicality" in which internal standard compete with the external, and the subjective with the objective. Whether an instrument has been delivered is in modern law a question of intention. It is generally agreed today that delivery does not necessarily involve a manual transfer of the deed, provided the grantor indicates an intention otherwise that the deed shall take effect, though perhaps the manual act, or the lack of it, is evidence of that intention. The delivery of a conveyance means merely the expression, by word or act, of an intention that the instrument shall be legally operative as a binding instrument.
Glenn A. McCleary,
Some Problems Involved in Conditional Deliveries of Deeds,
43 Bulletin Law Series.
Available at: https://scholarship.law.missouri.edu/ls/vol43/iss1/3