Thanks to Robert for pointing me to this airport!
It’s hidden a little bit, but the airport guide lists that the Airport Service Counter has stamps for sale and a drop box nearby.
According to the Terminal Map, the Service Counter is pre-security in the lobby between the Tailwind and the car rental counters.
Robert updated me and said it’s a silver mailbox between the service counter and the car rental desks.
Last updated 21 November 2021