Good morning folks
Just turned on my new toy

a surveillance cam so I can see ups get here and sign for stuff
I've had one for the house for quite some time now... comes in pretty handy on occasion.
If you've mounted it inside looking out a window, just know that the IR lights will reflect back off of the window effectively blinding the camera if you try using it at night... so that part may end up being useless for night surveillance. I've been keeping an eye out for one that uses one of the Sony sensors that works really well in low light without the need of an IR light, well enough to even see some color in some cases... but so far I haven't seen one I'm willing to pay for yet.
We've also got some at work... I often use the first floor camera for the same reason you mention, checking to see when one of the carrier's show up with packages. They are all ( total of 6 so far ) tied into a video surveillance server for recording, so if needed, we've got evidence for any crime that may happen in the building. We also keep one camera pointing out a window to the S / SW... that we primarily use to watch the incoming weather, it was actually setup to as a server monitor for the 5 servers and networking connections for the building but is seldom needed for that purpose. If I replace my home camera, I may donate it for pointing out of a northern facing window to catch weather coming in from that direction.