I have been copy/pasting county property information into LG Pass directly via add mailing 1 at a time

I have been copy/pasting county property information into LG Pass directly via add mailing 1 at a time... Not sure about another way to do it... Is this what everyone else it doing too? From Scott Todd: Use "import mailing," as I show you in the session three video.
You can also learn how to do it here, and in the video below