There is a common myth in the community to the effect that the tendering of a resignation to an employer by an employee is not effective until it is accepted by the employer. This is completely wrong.
In State of New South Wales v Paige  NSWCA 235 pp 277, 279, it was held:
“Subject to any contractual or statutory provision to the contrary, the act of resignation from employment, or from membership of an organisation, is a unilateral act that takes effect in accordance with its terms and does not depend upon its acceptance by the person or body to whom the resignation is directed. This common law principle is a reflection of the significance that the common law has always attached to personal autonomy.”
And see Kearney v Raymark Roofing Pty Ltd (2015) FWC 3705 delivered 10 June 2015 per Wells DP