KL M-class
 

What is KL's M-class? Flew a recent award tickets, BP shows M as class of service, but according to DL, M-class on KL earns miles (nothing has posted yet...wishful thinking?)

BPs on AF/KL/AZ tend not to show the actual class paid, in my experience. Right now, AF/KL have just aligned fare buckets, so you've got the mess of some fares that were booked before the alignment for later travel, so the bucket might have been remapped or not. On an award ticket, I'd expect DL's systems to get it right in the end (unfortunately for you). It does take a couple of days for partner flights to post, of course.

Yep, wishful thinking. :)

KL boarding passes show either M for economy or C for biz. That does not indicate the actual fare class, but rather that you are in the economy cabin. Mileage earning is given by the actual fare class.