Returned Sheriffs letters.

I have had several bad addresses....7 or so, which have to be resent. But zero have been returned for postage due. But then, unlike the NY presentments which all 112 came back to me, I learned an $$ lesson. Don't mail them from the same location in bulk, and all on the same day. Do the mailing by 4 or 5 people from different counties, different locations and on different days.....take a week. Don't make red flagging easy.