I had a delivery in an apartment building on a major street yesterday. This was my third attempt. Pulling up to the building, I see the infonotices from the past 2 days. there is intercomm or call box to get a hold of the tenants inside. As I'm filling out the 3rd infonotice, advising the recipient the package is being returned a letter carrier walks up on me, opens a lock box discreetly tucked in the wall, inside is a key to the main door. I followed him in and made the delivery. One of these would make my job so much easier, I have about 10 send agains a day because of this. Does anybody have one of these keys?