Print Merge

Hello. I'm running a print Merge from .CSV file created from Excel. I am placing names and addresses in my document from the file for a postcard mailing. I place the fields but when I run the print Merge to a new document the fields are either overlapped or spaced too far apart. In other words the field are not auto spacing bases in their length. I've tried moving the fields around, resizing, changing alignment etc but no results. Hope someone can help. Thank you .