[imp] Sent mail folder?

[FreeBSD user]

> Zitat von FreeBSD user <freebsd@XtremeDev.com>:
>
> > This is probably a RTFM question, but it is one that I haven't been
> > able
> > to resolve/find with a grep through the configs. But how do you set
IMP
> > to
> > always save a copy of a sent email in a sentmail folder? Thanks.
>
> Options -> Personal Information -> Identities
>
> Jan.

I have in my prefs.conf:

$_prefs['save_sent_mail'] = array(
    'value' => 1,
    'locked' => false,
    'shared' => true,
    'type' => 'implicit'
);


I would like to have this set to true by default for all users. I guess I
don't see offhand how to enable that in prefs.conf