What happens if a serve hits the net post in beach tennis?

If a serve hits the net post and lands in the correct service box, it is a let and the serve is retaken. If it hits the net post and does not land in the correct service box, it is a service fault.

Full Explanation

Per ITF Beach Tennis Rules Rule 7, a serve that touches the net (including the net cord and the top of the post) and lands in the correct service box results in a let; the service is retaken without counting as a fault. If the ball hits the net post or the supporting structure and lands outside the service box or does not reach the service box, it is a service fault. The net post and the net cord are part of the net for the purpose of the let call. During play (after the serve), a ball that hits the net post and passes over or around it into the opponent's court is in play if it lands within the boundaries; this is an unusual but valid scenario.

Ruleset: ITF  |  Rule Reference: ITF Beach Tennis Rules, Rule 7.8 (Let) and Rule 2 (The Net)