Re: C-x h o in Rmail ?

[Eli Zaretskii]

> From: Xavier Maillard <xavier@maillard.im>
> Date: Tue, 29 May 2018 21:29:04 +0200
> 
> due to limitations, I had to switch back to Rmail as my mail reader. As
> I am an ancient Rmail user, that's not really a problem. Habits gets
> back quicker than I thought.
> 
> I am just frustrated with something I am pretty sure was possible:
> output a bunch a messages into another Rmail file using this
> keysequence: C-x h o ~/.cache/mail/ANOTHER-RMAIL-FILE RET
> 
> So, Rmail users, did I dream it at some point ?

And "C-x h" in this context does what, exactly, according to your
dream?  You say "a bunch of messages", which presumably requires to
specify that bunch in some way.  How did "C-x h" do that?