●バックアップ取得
[root@web2 ~]#  cp -p /etc/postfix/main.cf /etc/postfix/main.cf.org

●main.cf編集

以下の内容に変更

[root@web2 ~]# diff -c /etc/postfix/main.cf /etc/postfix/main.cf.org
*** /etc/postfix/main.cf        Thu Nov 24 11:29:34 2011
--- /etc/postfix/main.cf.org    Wed Jun  1 01:29:21 2011
***************
*** 68,74 ****
  #
  #myhostname = host.domain.tld
  #myhostname = virtual.domain.tld
- myhostname = web2.i-generation.jp

  # The mydomain parameter specifies the local internet domain name.
  # The default is to use $myhostname minus the first component.
--- 68,73 ----
***************
*** 76,82 ****
  # parameters.
  #
  #mydomain = domain.tld
- mydomain = i-generation.jp

  # SENDING MAIL
  #
--- 75,80 ----
***************
*** 92,98 ****
  # to recipient addresses that have no @domain part.
  #
  #myorigin = $myhostname
! myorigin = $mydomain

  # RECEIVING MAIL

--- 90,96 ----
  # to recipient addresses that have no @domain part.
  #
  #myorigin = $myhostname
! #myorigin = $mydomain

  # RECEIVING MAIL

***************
*** 106,115 ****
  #
  # Note: you need to stop/start Postfix when this parameter changes.
  #
! inet_interfaces = all
  #inet_interfaces = $myhostname
  #inet_interfaces = $myhostname, localhost
! #inet_interfaces = localhost

  # The proxy_interfaces parameter specifies the network interface
  # addresses that this mail system receives mail on by way of a
--- 104,113 ----
  #
  # Note: you need to stop/start Postfix when this parameter changes.
  #
! #inet_interfaces = all
  #inet_interfaces = $myhostname
  #inet_interfaces = $myhostname, localhost
! inet_interfaces = localhost

  # The proxy_interfaces parameter specifies the network interface
  # addresses that this mail system receives mail on by way of a
***************
*** 154,161 ****
  #
  # See also below, section "REJECTING MAIL FOR UNKNOWN LOCAL USERS".
  #
! #mydestination = $myhostname, localhost.$mydomain, localhost
! mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
  #mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain,
  #     mail.$mydomain, www.$mydomain, ftp.$mydomain

--- 152,159 ----
  #
  # See also below, section "REJECTING MAIL FOR UNKNOWN LOCAL USERS".
  #
! mydestination = $myhostname, localhost.$mydomain, localhost
! #mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
  #mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain,
  #     mail.$mydomain, www.$mydomain, ftp.$mydomain

***************
*** 409,415 ****
  # "Maildir/" for qmail-style delivery (the / is required).
  #
  #home_mailbox = Mailbox
! home_mailbox = Maildir/

  # The mail_spool_directory parameter specifies the directory where
  # UNIX-style mailboxes are kept. The default setting depends on the
--- 407,413 ----
  # "Maildir/" for qmail-style delivery (the / is required).
  #
  #home_mailbox = Mailbox
! #home_mailbox = Maildir/

  # The mail_spool_directory parameter specifies the directory where
  # UNIX-style mailboxes are kept. The default setting depends on the
***************
*** 667,677 ****
  # readme_directory: The location of the Postfix README files.
  #
  readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES
-
- smtpd_sasl_auth_enable = yes
- smtpd_sasl_local_domain = $myhostname
- smtpd_recipient_restrictions =
-     permit_mynetworks
-     permit_sasl_authenticated
-     reject_unauth_destination
-
--- 665,667 ----


●saslauthd起動
[root@web2 ~]# /etc/rc.d/init.d/saslauthd start
Starting saslauthd:                                        [  OK  ]

●saslauthd自動起動設定
[root@web2 ~]# chkconfig saslauthd on
[root@web2 ~]# chkconfig --list saslauthd
saslauthd       0:off   1:off   2:on    3:on    4:on    5:on    6:off

●メールボックス作成
[root@web2 ~]# mkdir -p /etc/skel/Maildir/new
[root@web2 ~]# mkdir -p /etc/skel/Maildir/cur
[root@web2 ~]# mkdir -p /etc/skel/Maildir/tmp

●sendmail停止
[root@web2 ~]# /etc/rc.d/init.d/sendmail stop
Shutting down sm-client:                                   [  OK  ]
Shutting down sendmail:                                    [  OK  ]

●sendmail自動起動設定解除
[root@web2 ~]# chkconfig --list sendmail
sendmail        0:off   1:off   2:on    3:on    4:on    5:on    6:off
[root@web2 ~]# chkconfig  sendmail off
[root@web2 ~]# chkconfig --list sendmail
sendmail        0:off   1:off   2:off   3:off   4:off   5:off   6:off

●メールサーバ切り替え
[root@web2 ~]# alternatives --config mta

There are 2 programs which provide 'mta'.

  Selection    Command
-----------------------------------------------
*+ 1           /usr/sbin/sendmail.sendmail
   2           /usr/sbin/sendmail.postfix

Enter to keep the current selection[+], or type selection number: 2  ←2を選択

●postfix起動
[root@web2 ~]# /etc/rc.d/init.d/postfix start
Starting postfix:                                          [  OK  ]

●Postfix自動起動設定
[root@web2 ~]# chkconfig --list postfix
postfix         0:off   1:off   2:on    3:on    4:on    5:on    6:off
[root@web2 ~]# chkconfig postfix on
[root@web2 ~]# chkconfig --list postfix
postfix         0:off   1:off   2:on    3:on    4:on    5:on    6:off