DAY1 : 必要最小限の設定 (mail)

前準備

1. Postfix インストール

   # yum install postfix Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * addons: www.ftp.ne.jp * base: www.ftp.ne.jp * extras: www.ftp.ne.jp * updates: www.ftp.ne.jp Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package postfix.i386 2:2.3.3-2.1.el5_2 set to be updated --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: postfix i386 2:2.3.3-2.1.el5_2 base 3.6 M Transaction Summary ================================================================================ Install 1 Package(s) Upgrade 0 Package(s) Total download size: 3.6 M Is this ok [y/N]: y Downloading Packages: postfix-2.3.3-2.1.el5_2.i386.rpm | 3.6 MB 00:20 Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Installing : postfix 1/1 Installed: postfix.i386 2:2.3.3-2.1.el5_2 Complete!

   同様に system-switch-mail もインストールしておきます。

2. MTAの切り替え
   system-switch-mail により、MTA を sendmail から Postfix に変更します。
   矢印キーと、タブで当該部分を選択し、[ OK ]で　[Enter]を押せば変更できます。

設定変更抜粋　(/etc/postfix/mail.cf)

1. myhostname

   # INTERNET HOST AND DOMAIN NAMES # # The myhostname parameter specifies the internet hostname of this # mail system. The default is to use the fully-qualified domain name # from gethostname(). $myhostname is used as a default value for many # other configuration parameters. # #myhostname = host.domain.tld #myhostname = virtual.domain.tld # ycos 2010/12/26 myhostname = smtp.t033030.la.net

2. mydomain

   # The mydomain parameter specifies the local internet domain name. # The default is to use $myhostname minus the first component. # $mydomain is used as a default value for many other configuration # parameters. # #mydomain = domain.tld # ycos 2010/12/26 mydomain = t033030.la.net

3. myorigin

   # SENDING MAIL # # The myorigin parameter specifies the domain that locally-posted # mail appears to come from. The default is to append $myhostname, # which is fine for small sites. If you run a domain with multiple # machines, you should (1) change this to $mydomain and (2) set up # a domain-wide alias database that aliases each user to # user@that.users.mailhost. # # For the sake of consistency between sender and recipient addresses, # myorigin also specifies the default domain name that is appended # to recipient addresses that have no @domain part. # #myorigin = $myhostname # ycos 2010/12/26 myorigin = $mydomain

4. inet_interfaces

   # RECEIVING MAIL # The inet_interfaces parameter specifies the network interface # addresses that this mail system receives mail on. By default, # the software claims all active interfaces on the machine. The # parameter also controls delivery of mail to user@[ip.address]. # # See also the proxy_interfaces parameter, for network addresses that # are forwarded to us via a proxy or network address translator. # # Note: you need to stop/start Postfix when this parameter changes. # #inet_interfaces = all #inet_interfaces = $myhostname #inet_interfaces = $myhostname, localhost #inet_interfaces = localhost # ycos 2010/12/26 inet_interfaces = all

5. mydestination

   # 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 # ycos 2010/12/26 mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain

6. mynetworks

   # Alternatively, you can specify the mynetworks list by hand, in # which case Postfix ignores the mynetworks_style setting. # # Specify an explicit list of network/netmask patterns, where the # mask specifies the number of bits in the network part of a host # address. # # You can also specify the absolute pathname of a pattern file instead # of listing the patterns here. Specify type:table for table-based lookups # (the value on the table right-hand side is not used). # #mynetworks = 168.100.189.0/28, 127.0.0.0/8 #mynetworks = $config_directory/mynetworks #mynetworks = hash:/etc/postfix/network_table # ycos 2010/12/26 mynetworks = 10.20.0.0/16, 127.0.0.0/8

動作確認

• OK パターン (同じネットワークのPCから - インバウンド)

  [student@hxxx ~]$ telnet 10.20.33.30 25 Trying 10.20.33.30... Connected to h030.s33.la.net (10.20.33.30). Escape character is '^]'. 220 smtp.t033030.la.net ESMTP Postfix ehlo t033xxx.la.net 250-smtp.t033030.la.net 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN mail from:ycos@t033xxx.la.net # 同じネットワークから 250 2.1.0 Ok rcpt to:student@t033030.la.net # 同じネットワークへ 250 2.1.5 Ok data 354 End data with <CR>lt;LF>lt;CR>lt;LF> Hello! . 250 2.0.0 Ok: queued as 501E52EC06 quit 221 2.0.0 Bye Connection closed by foreign host.

• OK パターン（アウトバウンド）

  # telnet 10.20.33.30 25 Trying 10.20.33.30... Connected to 10.20.33.30 (10.20.33.30). Escape character is '^]'. 220 smtp.t033030.la.net ESMTP Postfix ehlo localdomain 250-smtp.t033030.la.net 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN mail from:root@t033040.la.net # 同じネットワークから 250 2.1.0 Ok rcpt to:ycos001@yahoo.co.jp # 外部ネットワークへ 250 2.1.5 Ok data 354 End data with <CR>lt;LF>lt;CR>lt;LF> Hello . 250 2.0.0 Ok: queued as 431EB2EC06 quit 221 2.0.0 Bye Connection closed by foreign host.

• NG パターン (オープンリレー）

  D:\> telnet 10.20.33.30 25 220 smtp.t033030.la.net ESMTP Postfix ehlo wbiznet.co.jp 250-smtp.t033030.la.net 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN mail from:yakoshi@wbiznet.co.jp # 外部ネットワークから 250 2.1.0 Ok rcpt to:ycos001@yahoo.co.jp # 外部ネットワークへ 554 5.7.1 <ycos001@yahoo.co.jp> Relay access denied