漫長歲月經我多年的學習研究CentOS postfix系統，發現你可能會遇到CentOS postfix安裝問題，這里將介紹CentOS postfix安裝問題的解決方法，CentOS Linux和與之對應版本號的RHEL發行版具有軟件包級別的二進制兼容性，即某個RPM軟件包如果可以安裝運行在RHEL產品中，就可以正常地安裝運行在對應版本的CentOS Linux中。講解CentOS postfix學習安裝。

A、CentOS postfix下載軟件包
[root@localhost i386]# cd
[root@localhost ~]# wget http://ftp.wl0.org/official/2.5/SRPMS/postfix-2.5.4-2.src.rpm
[root@localhost ~]# rpm -ivh postfix-2.5.4-2.src.rpm
[root@localhost ~]# cd $SPEC
編輯postfix.spec 修改下面的選項
%define distribution rhel-5.0
%define with_mysql_redhat 1
%define with_sasl         2
%define with_vda          1

B、CentOS postfix安裝創建rpm
[root@localhost SPECS]# rpmbuild -bb postfix.spec
[root@localhost RPMS]# cd $RPMS/i386
[root@localhost i386]# rpm -ivh postfix-2.5.4-2.rhel4.i386.rpm

C、CentOS postfix安裝切換mta
[root@localhost i386]# alternatives --config mta （選擇2，postfix）
[root@localhost i386]# rpm -e sendmail
[root@localhost i386]# cd /usr/sbin/
[root@localhost sbin]# mv sendmail sendmail.bak
[root@localhost sbin]# newaliases
[root@localhost sbin]# ln -s sendmail.postfix sendmail

D、CentOS postfix安裝配置
[root@localhost ~]# cd /etc/postfix/
[root@localhost postfix]# mv main.cf main.cf.bak
[root@localhost postfix]# vim main.cf
輸入下面的內容：
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
mail_owner = postfix
unknown_local_recipient_reject_code = 550
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5

sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = /usr/share/doc/postfix-2.5.2-documentation/html
manpage_directory = /usr/share/man
sample_directory = /etc/postfix
readme_directory = /usr/share/doc/postfix-2.5.2-documentation/readme
alias_database = hash:/etc/postfix/aliases
alias_maps = hash:/etc/postfix/aliases
myhostname = mail.yiyou.org
mydomain = yiyou.org
mydestination = $myhostname
smtpd_banner = yiyou.org ESMTP Mail System
message_size_limit = 14680064
virtual_alias_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf
virtual_mailbox_base = /home/data/domains
virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_mailbox_limit_maps = mysql:/etc/postfix/mysql_virtual_limit_maps.cf
virtual_transport = maildrop:
maildrop_destination_recipient_limit = 1

#sasl
smtpd_sasl_auth_enable = yes
smtpd_sasl2_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes

smtpd_recipient_restrictions =
permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_destination,
reject_unauth_pipelining,
reject_invalid_hostname

復制extman/docs 目錄的cf 文件到/etc/postfix
[root@localhost postfix]# cp /root/extman-0.2.5b1/docs/mysql_virtual_* .
因為CentOS postfix安裝配置文件的用戶、密碼與數據庫時一樣，所以不用修改。
[root@localhost postfix]# service postfix start

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