I understand the meaning but I'm not sure we have anything similar in LatAm. My atempt would be: una bandeja/urna/caja para dejar X cosa. Context: Tips to conduct a successful customer satisfaction survey. One of the tips is:You can also use a drop-off box for participants to drop their forms. Thanks for your help!
Drop-off box, it can be used for almost anything. It is a box with a lid that can be locked and has a slot cut in it for dropping in the forms. Although, it can probably be used to describe almost any sort of secure container with a slot for putting in paper forms or small packages.
Suggestion box = a drop-off box used to accept suggestions
But, in this case, they are not putting in suggestions so I don't recommend that you use the word sugerencias...if buzón describes the type of box (lockable lid with a slot), then perhaps buzón by itself is fine...Por favor, dejan los impresos de encuesta en el buzón. Espero que mi español no sea demasiado horrible
Me suena a "buzón de sugerencias".