if with sumproduct or countif or Something else???

I have orders that get sent out daily and are supposed to be received signed within 30 days. Our system tracks the dates they were sent and received. I need to calculate how many are received within 30 days, over 30 days and outstanding. Also along with the count of each, looking to get the percentages, but I can do that after the counts.

So for the total sent for February, I am using =SUMPRODUCT((Detail!K2:K12565>=40940)*(Detail!K2:K12565<40969))
My received column is O. How do I find out the number of orders sent in February and returned within 30 days? Also may want to find out how many sent out in February and were received before April 1.

That formula only tells me how many I sent. I need to determine how many I received back.

I was able to determine how many I received back in February and March by using
=COUNTIFS(Detail!$K:$K,">=40940",Detail!$K:$K,"<40969",Detail!$O:$O,"<41000")

But I need to change it to the total I received back within 30 days from the date sent.