mutt with postfix ~/Maildir

Configure mutt
on systems with a postfix MTA and system user accounts

eg set in /etc/postfix/
home_mailbox = Maildir/

then add the followin to the end of /etc/Muttrc
set folder="~/Maildir"
set mask="!^\\.[^.]"
set mbox="~/Maildir"
set record="+.Sent"
set postponed="+.Drafts"
set spoolfile="~/Maildir"

the user's mailboxes are in their home directories instead of /var/mail/mailuser and look like directory structures instead of flat files eg.
# ls /home/testuser/Maildir/
cur  new  tmp

partially true for debian wheezy links:
debian Maildir Configuration
debian postfix

mutt with postfix and Maildir