[root@linux ~]# useradd -s /sbin/nologin fedora 
[root@linux ~]# passwd fedora 
Changing password for user fedora.
New UNIX password: xxxxxxxxxxx 
Retype new UNIX password: xxxxxxxxxxx 
passwd: all authentication tokens updated successfully.

[root@linux ~]# saslpasswd2 -u mountainbigroad.jp -c fedora 
Password: xxxxxxxxxxx 
Again (for verification): xxxxxxxxxxx 

# SMTP-AUTH 用パスワードの確認
[root@linux ~]# sasldblistusers2 
fedora@mountainbigroad.jp: userPassword

# パスワードファイルの権限変更 ( 初回のみ実施します。)
[root@linux ~]# chgrp postfix /etc/sasldb2 
[root@linux ~]# chmod 640 /etc/sasldb2 

[root@linux ~]# saslpasswd2 -d fedora -u mountainbigroad.jp 

[root@linux ~]# userdel -r fedora 

[root@linux ~]# vi /etc/aliases 

#
#  Aliases in this file will NOT be expanded in the header from
#  Mail, but WILL be visible over networks or from /bin/mail.
#
#       >>>>>>>>>>      The program "newaliases" must be run after
#       >> NOTE >>      this file is updated for any changes to
#       >>>>>>>>>>      show through to sendmail.
#

# Basic system aliases -- these MUST be present.
mailer-daemon:  postmaster
postmaster:     root

# General redirections for pseudo accounts.
bin:            root
daemon:         root
  :
  :
# Person who should get root's mail
#root:          marc
# 管理者(root)宛てのメールをfedoraに転送
root:           fedora

[root@linux ~]# postalias /etc/aliases 
/etc/aliases: 77 aliases, longest 18 bytes, 787 bytes total