Can I install your fence letterboxes horizontally? Abbey October 13, 2017 01:17 Follow Yes you can. Our fence letterboxes are designed to be installed both vertically and horizontally. Related articles I ordered a timber panel letterbox, where are the anchor posts? What material is your timber panel letterboxes? My keys aren't working I've received my product but I can't find my keys I ordered a concrete pillar letterbox, where is the front panel? Comments 0 comments Article is closed for comments.