参考http://wiki.centos.org/HowTos/postfix和http://wiki.centos.org/HowTos/postfix_sasl和http://technet.microsoft.com/en-us/library/aa995718%28EXCHG.65%29.aspx
安装所需软件包：
yum install postfix dovecot system-switch-mail
修改之前的postfix的配置：
[root@localhost postfix]# grep -v '^#' /etc/postfix/main.cf | grep . queue_directory = /var/spool/postfix command_directory = /usr/sbin daemon_directory = /usr/libexec/postfix mail_owner = postfix inet_interfaces = localhost mydestination = $myhostname, localhost.$mydomain, localhost unknown_local_recipient_reject_code = 550 alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases debug_peer_level = 2 debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin xxgdb $daemon_directory/$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 = no manpage_directory = /usr/share/man sample_directory = /usr/share/doc/postfix-2.3.3/samples readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES
[root@localhost postfix]# grep -v '^#' /etc/postfix/master.cf | grep .
smtp inet n - n - - smtpd
pickup fifo n - n 60 1 pickup
cleanup unix n - n - 0 cleanup
qmgr fifo n - n 300 1 qmgr
tlsmgr unix - - n 1000? 1 tlsmgr
rewrite unix - - n - - trivial-rewrite
bounce unix - - n - 0 bounce
defer unix - - n - 0 bounce
trace unix - - n - 0 bounce
verify unix - - n - 1 verify
flush unix n - n 1000? 0 flush
proxymap unix - - n - - proxymap
smtp unix - - n - - smtp
relay unix - - n - - smtp
-o fallback_relay=
showq unix n - n - - showq
error unix - - n - - error
discard unix - - n - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - n - - lmtp
anvil unix - - n - 1 anvil
scache unix - - n - 1 scache
maildrop unix - n n - - pipe
flags=DRhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient}
old-cyrus unix - n n - - pipe
flags=R user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -m ${extension} ${user}
cyrus unix - n n - - pipe
user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -r ${sender} -m ${extension} ${user}
uucp unix - n n - - pipe
flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
ifmail unix - n n - - pipe
flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp unix - n n - - pipe
flags=Fq. user=foo argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient
生成ssl密钥：
um install crypto-utils genkey --days 365 mail.example.com
复制生成的密钥文件到postfix的ssl目录和dovecot
生成base64的用户密码用以测试：
$perl -MMIME::Base64 -e 'print encode_base64("\000user\000password");'
AHVzZXIAcGFzc3dvcmQ=
$ perl -MMIME::Base64 -e 'print decode_base64("AHVzZXIAcGFzc3dvcmQ=");'
userpassword
改动之后的/etc/postfix/main.cf,/etc/postfix/master.cf和/dev/dovecot.conf文件：
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
mail_owner = postfix
myhostname = dqatelier.com
mydomain = dqatelier.com
myorigin = $myhostname
inet_interfaces = $myhostname, localhost
mydestination = $myhostname, localhost.$mydomain, localhost
local_recipient_maps = $alias_maps
unknown_local_recipient_reject_code = 550
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
xxgdb $daemon_directory/$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 = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.3.3/samples
readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES
smtpd_sasl_local_domain =
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_security_options = noanonymous
smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination
smtpd_tls_auth_only = no
smtp_use_tls = yes
smtpd_use_tls = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
home_mailbox = Maildir/
mailbox_command =
0.0.0.0:smtp inet n - - - - smtpd
0.0.0.0:smtps inet n - n - - smtpd
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
pickup fifo n - n 60 1 pickup
cleanup unix n - n - 0 cleanup
qmgr fifo n - n 300 1 qmgr
tlsmgr unix - - n 1000? 1 tlsmgr
rewrite unix - - n - - trivial-rewrite
bounce unix - - n - 0 bounce
defer unix - - n - 0 bounce
trace unix - - n - 0 bounce
verify unix - - n - 1 verify
flush unix n - n 1000? 0 flush
proxymap unix - - n - - proxymap
smtp unix - - n - - smtp
relay unix - - n - - smtp
-o fallback_relay=
showq unix n - n - - showq
error unix - - n - - error
discard unix - - n - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - n - - lmtp
anvil unix - - n - 1 anvil
scache unix - - n - 1 scache
maildrop unix - n n - - pipe
flags=DRhu user=vmail argv=/usr/local/bin/maildrop -d ${recipient}
old-cyrus unix - n n - - pipe
flags=R user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -m ${extension} ${user}
cyrus unix - n n - - pipe
user=cyrus argv=/usr/lib/cyrus-imapd/deliver -e -r ${sender} -m ${extension} ${user}
uucp unix - n n - - pipe
flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
ifmail unix - n n - - pipe
flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp unix - n n - - pipe
flags=Fq. user=foo argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient
protocol imap {
}
protocol pop3 {
}
protocol lda {
postmaster_address = postmaster@example.com
}
auth_verbose = yes
auth default {
mechanisms = plain
passdb pam {
}
userdb passwd {
}
user = root
socket listen {
client {
path = /var/run/dovecot/auth-client
mode = 0660
user = postfix
group = postfix
}
}
}
dict {
}
plugin {
}
重启dovecot服务，重启postfix服务，重启saslauthd服务。不要忘记用system-switch-mail把默认的MTA切换成postfix。
添加用户，adduser，把用户加到/etc/alias里边，然后重建alias库，命令是newalias。
测试smtp服务：
$ telnet localhost 25 Trying 127.0.0.1... Connected to localhost.localdomain (127.0.0.1). Escape character is '^]'. 220 mail.example.com ESMTP Postfix EHLO example.com 250-mail.example.com 250-PIPELINING 250-SIZE 20480000 250-VRFY 250-ETRN 250-AUTH PLAIN LOGIN 250-AUTH=PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN AUTH PLAIN AHRlc3QAdGVzdDEyMzQ= 235 2.0.0 Authentication successful quit 221 2.0.0 Bye Connection closed by foreign host.
测试pop3服务：
telnet caishu.name 110 Trying 122.200.71.101... Connected to caishu.name (122.200.71.101). Escape character is '^]'. +OK Dovecot ready. auth login + VXNlcm5hbWU6 d2FuZ2Rpbmc= + UGFzc3dvcmQ6 MnNoZW5hbjIxMg== +OK Logged in. list