sorting messages by thread

Hi,

I'm new to mh, and I have several questions. Please forgive me if
they're stupid.

My first question is this: Is it possible to sort messages by threads
(like in Mutt, for instance; the replies to each mail appear immediately
after the mail itself). I didn't find any obvious way to do it with
sortm. If not possible directly, maybe there is some script that does
it?

Thanks,
Moshe