/etc/nmh/scan.mailx is in nmh 1.7.1~RC3-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 | %<(cur)>%| %>\
%<{status} %|N%>\
%<{replied}R%?{encrypted}E%| %>\
%4(msg) \
%<(mymbox{from})%<{to}To: %13(unquote(decode(friendly{to})))%>%>\
%<(zero)%17(unquote(decode(friendly{from})))%> \
%3(day{date}) %3(month{date}) %02(mday{date}) \
%02(hour{date}):%02(min{date}) \
%(decode{subject})
|