Spitting a Mailbox into separate files with formail

[Vidol Loeung <fedora.kh@xxxxxxxx>]

Dear All:

A long time ago, I used to be able to split a mailbox into separate text
files with this command:

cat $MAIL | formail -ds 'sh -c cat > msg.$FILENO'

Now, when I tried it again on Fedora, it did not work.

Could you please help me?

Regards,
Vidol