Good seal and denim nailing strip.

@Stephen Lynch  My mom lives in the area, but I get rent paid through etransfer or post dated cheques and I can deal with problems over the phone or email.

Given that I also have their phone number, should I also give them a call?

They have to connect to an internet connection but you can easily solve that by setting up Wi-Fi in the house or using a cell phone hotspot.

A more conservative approach would be to put on the sign “looking to buy your house” and your phone number....this would look more like a “we buy houses” sign which most are used to seeing.  

I highly recommend a phone call.

Our property is in a small town so not everyone has a computer but they do have a smart phone.

Found it by prospecting over the phone.

Maybe they switched phone carriers, maybe they are on vacation and out of the country so no cell service, etc.

They are running away from their phone calls.