Fixed order of headers in Rmail messages

[irek]

Hello.  Each Rmail message have headers printed in different order.
Reason for that is obvious but I was looking for convenient way to have
chosen headers always in the same order in all messages.

I don't see any Rmail variable or function that could help with sorting
except for `rmail-show-message-hook' that could be used to modify each
message when displayed but that's not the way I would like to go.

Maybe I missed something or maybe there is a way to do this on movemail
level or other mailutils program.  I was looking there but couldn't find
anything.  Any ideas or suggestions?