Maildir Delivery

User environment:

/etc/login.defs:       MAIL_FILE Maildir/
/etc/csh.login:        setenv MAIL $HOME/Maildir
/etc/profile:          export MAIL="${HOME}/Maildir/"

Postfix default delivery:

/etc/postfix/main.cf:  home_mailbox = Maildir/

Maildrop default delivery:

/etc/maildroprc:       DEFAULT="$HOME/Maildir"

deprecated

/etc/login.defs:       MAIL_DIR Maildir/