You will need to make sure it is at an address not the same as your home (because it is not looked upon favorably by the lending world) and the phone will need to be registered in the 411 directory.

We weeded out the federal and state government and big timber concerns.. so basically all the private owners.. so from there he would type in the owners name and address.this took about a year and 50k or so paying for his wages and hotel rooms.Then once that data was collected I had my secretary run each lead through the reverse directory or phone book to get phone numbers.. we collect 95% of the leads phone number ( remember  this when EVERYONE had land lines) also rural areas always have landlines.  

Because remember...you are sending these out to a list you or someone else has curated.