digest-headers.awk (285B)
1 #/^--- --- --- [0-9]/,/^$/ { 2 /^Received: /,/^$/ { 3 if ($1 == "From:" || $1 == "Subject:" || $1 == "Date:" || 4 $1 == "from:" || $1 == "subject:" || $1 == "date:" || 5 $1 == "FROM:" || $1 == "SUBJECT:" || $1 == "DATE:" || 6 $1 == "---" || NF == 0) 7 print; 8 next 9 } 10 { print }