Hummingbird, I mailed some pear butter to a friend, and wrapped it carefully, bubbled and more. There is the jar lid, which is all that is generally needed, but when mailing, it is recommended to put the screw cap back on (if you removed it in the first place), to insure that if the jar lid is displaced at any point, the jar/contents/moisture do not mess up the entire box. My mailing was still a success and yours will probably will be too.