参考：http://www.jimmy.co.at/weblog/?p=52
mail.info 日志如下：
warning: SASL authentication failure: cannot connect to saslauthd server: No such file or directory
SASL LOGIN authentication failed: generic failure
lost connection after AUTH from unknown
disconnect from unknown
解决办法是：
将/etc/default/saslauthd文件中的：
#OPTIONS="-c -m /var/run/saslauthd"
改为：
OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd"
并执行如下命令：
/etc/init.d/saslauthd restart
rm -r /var/run/saslauthd/
ln -s /var/spool/postfix/var/run/saslauthd /var/run
chgrp sasl /var/spool/postfix/var/run/saslauthd
adduser postfix sasl
/etc/init.d/saslauthd restart
/etc/init.d/postfix restart
即可。
配置文件如下：
root@ubuntu:~# cat /etc/default/saslauthd
#
# Settings for saslauthd daemon
# Please read /usr/share/doc/sasl2-bin/README.Debian for details.
#
# Should saslauthd run automatically on startup? (default: no)
START=yes
# Description of this saslauthd instance. Recommended.
# (suggestion: SASL Authentication Daemon)
DESC="SASL Authentication Daemon"
# Short name of this saslauthd instance. Strongly recommended.
# (suggestion: saslauthd)
NAME="saslauthd"
# Which authentication mechanisms should saslauthd use? (default: pam)
#
# Available options in this Debian package:
# getpwent -- use the getpwent() library function
# kerberos5 -- use Kerberos 5
# pam -- use PAM
# rimap -- use a remote IMAP server
# shadow -- use the local shadow password file
# sasldb -- use the local sasldb database file
# ldap -- use LDAP (configuration is in /etc/saslauthd.conf)
#
# Only one option may be used at a time. See the saslauthd man page
# for more information.
#
# Example: MECHANISMS="pam"
MECHANISMS="shadow"
# Additional options for this mechanism. (default: none)
# See the saslauthd man page for information about mech-specific options.
MECH_OPTIONS=""
# How many saslauthd processes should we run? (default: 5)
# A value of 0 will fork a new process for each connection.
THREADS=5
# Other options (default: -c -m /var/run/saslauthd)
# Note: You MUST specify the -m option or saslauthd won't run!
#
# WARNING: DO NOT SPECIFY THE -d OPTION.
# The -d option will cause saslauthd to run in the foreground instead of as
# a daemon. This will PREVENT YOUR SYSTEM FROM BOOTING PROPERLY. If you wish
# to run saslauthd in debug mode, please run it by hand to be safe.
#
# See /usr/share/doc/sasl2-bin/README.Debian for Debian-specific information.
# See the saslauthd man page and the output of 'saslauthd -h' for general
# information about these options.
#
# Example for postfix users: "-c -m /var/spool/postfix/var/run/saslauthd"
#OPTIONS="-c -m /var/run/saslauthd"
OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd"
Postfix配置文件：
root@ubuntu:~# cat /etc/postfix/main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# TLS parameters
smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
myhostname = mail.example.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = localhost, $myhostname, localhost.example.com, example.com
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
smtpd_sasl_path = smtpd
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain =
smtpd_sasl_security_options = noanonymous
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
message_size_limit = 10728640
home_mailbox =
smtpd_sasl_type = cyrus
smtpd_sasl_authenticated_header = no
broken_sasl_auth_clients = yes
smtpd_sender_restrictions =
mailbox_command =
smtp_use_tls = no
smtpd_tls_received_header = no
smtpd_tls_mandatory_protocols = SSLv3, TLSv1
smtpd_tls_mandatory_ciphers = medium
smtpd_tls_auth_only = no
tls_random_source = dev:/dev/urandom
inet_protocols = ipv4
smtp_tls_note_starttls_offer = yes
smtpd_tls_loglevel = 1
smtpd_tls_session_cache_timeout = 3600s
relay_domains = $myorigin #需要这是relay_domains的设置，否则发送的邮件会列入到垃圾邮箱
smtpd配置文件：
root@ubuntu:~# cat /etc/postfix/sasl/smtpd.conf
pwcheck_method: saslauthd
mech_list: PLAIN LOGIN
log_level: 5
