请点击这里的链接：http://flurdy.com/docs/postfix/使用 posfix、courier、MySql 和 sasl 为我提供了一个具有 imap 功能的 Web 服务器，运行良好，但当我使用与连接 imap 服务器相同的用户 ID 和密码登录服务器发送消息时，它拒绝我登录 smtp 服务器。如果我没有为外发邮件服务器指定登录名，那么它将正常发送消息。postfix 日志中的错误是：
Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: connect from unknown[10.0.0.50]
Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: warning: SASL authentication failure: unable to canonify user and get auxprops
Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: warning: unknown[10.0.0.50]: SASL DIGEST-MD5 authentication failed: no mechanism available
Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: warning: unknown[10.0.0.50]: SASL LOGIN authentication failed: no mechanism available
我已经检查了 mysql 的所有用户名和密码。可能出了什么问题？
编辑：
以下是一些其他信息：
为 postfix、courier 和 sasl 安装了库：
aptitude install postfix postfix-mysql
aptitude install libsasl2-modules libsasl2-modules-sql libgsasl7 libauthen-sasl-cyrus-perl sasl2-bin libpam-mysql
aptitude install courier-base courier-authdaemon courier-authlib-mysql courier-imap courier-imap-ssl courier-ssl
这是我的 /etc/postfix/main.cf
myorigin = domain.com
smtpd_banner = $myhostname ESMTP $mail_name
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${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 = my hostname
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
local_recipient_maps =
mydestination =
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
mynetworks_style = host
# how long if undelivered before sending warning update to sender
delay_warning_time = 4h
# will it be a permanent error or temporary
unknown_local_recipient_reject_code = 450
# how long to keep message on queue before return as failed.
# some have 3 days, I have 16 days as I am backup server for some people
# whom go on holiday with their server switched off.
maximal_queue_lifetime = 7d
# max and min time in seconds between retries if connection failed
minimal_backoff_time = 1000s
maximal_backoff_time = 8000s
# how long to wait when servers connect before receiving rest of data
smtp_helo_timeout = 60s
# how many address can be used in one message.
# effective stopper to mass spammers, accidental copy in whole address list
# but may restrict intentional mail shots.
# but may restrict intentional mail shots.
smtpd_recipient_limit = 16
# how many error before back off.
smtpd_soft_error_limit = 3
# how many max errors before blocking it.
smtpd_hard_error_limit = 12
# Requirements for the HELO statement
smtpd_helo_restrictions = permit_mynetworks, permit
# Requirements for the sender details
smtpd_sender_restrictions = permit_sasl_authenticated, permit_mynetworks, warn_if_reject reject_non_fqdn_sender, reject_unknown_sender_domain, reject_unauth_pipelining, permit
# Requirements for the connecting server
smtpd_client_restrictions = reject_rbl_client sbl.spamhaus.org, reject_rbl_client blackholes.easynet.nl, reject_rbl_client dnsbl.njabl.org
# Requirement for the recipient address
smtpd_recipient_restrictions = reject_unauth_pipelining, permit_mynetworks, permit_sasl_authenticated, reject_non_fqdn_recipient, reject_unknown_recipient_domain, reject_unauth_destination, permit
smtpd_data_restrictions = reject_unauth_pipelining
# require proper helo at connections
smtpd_helo_required = yes
# waste spammers time before rejecting them
smtpd_delay_reject = yes
disable_vrfy_command = yes
# not sure of the difference of the next two
# but they are needed for local aliasing
alias_maps = hash:/etc/postfix/aliases
alias_database = hash:/etc/postfix/aliases
# this specifies where the virtual mailbox folders will be located
virtual_mailbox_base = /var/spool/mail/virtual
# this is for the mailbox location for each user
virtual_mailbox_maps = mysql:/etc/postfix/mysql_mailbox.cf
# and this is for aliases
virtual_alias_maps = mysql:/etc/postfix/mysql_alias.cf
# and this is for domain lookups
virtual_mailbox_domains = mysql:/etc/postfix/mysql_domains.cf
# this is how to connect to the domains (all virtual, but the option is there)
# not used yet
# transport_maps = mysql:/etc/postfix/mysql_transport.cf
virtual_uid_maps = static:5000
virtual_gid_maps = static:5000
# SASL
smtpd_sasl_auth_enable = yes
# If your potential clients use Outlook Express or other older clients
# this needs to be set to yes
broken_sasl_auth_clients = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain =
答案1
我偶然发现了一个与此非常相似的问题。解决方案是稍微修改 smtpd.conf 文件（位于 /etc/postfix/sasl）。
确实，flurdy.com 教程中有两个错误：
原始版本：
pwcheck_method: saslauthd
mech_list: plain login cram-md5 digest-md5
log_level: 7
allow_plaintext: true
auxprop_plugin: mysql # <-----
sql_engine: mysql
sql_hostnames: 127.0.0.1
sql_user: mail
sql_passw: mailPASSWORD # <----
sql_database: maildb
sql_select: select crypt from users where id='%u@%r' and enabled = 1
更正：
pwcheck_method: saslauthd
mech_list: plain login cram-md5 digest-md5
log_level: 7
allow_plaintext: true
auxprop_plugin: sql # <--- sql instead of mysql
sql_engine: mysql
sql_hostnames: 127.0.0.1
sql_user: mail
sql_passwd: mailPASSWORD # <---- sql_passwd instead of sql_passw
sql_database: maildb
sql_select: select crypt from users where id='%u@%r' and enabled = 1
希望这能解答你的问题
答案2
此症状表明您的 postfix 设置无法以合理的方式使用 SASL 库。
检查您是否有与您正在使用的机制（例如，普通机制）相对应的 SASL 机制库。例如，在 CentOS 5 中，这是通过安装单独的软件包来实现的（例如，如果您使用的是 Cyrus SASL，那么您需要名为 cyrus-sasl-plain 的软件包才能使用普通机制）。安装完成后，您应该在 postfix 的配置中拥有匹配的 SASL 参数。请参阅“man 5 postconf”以获取有关它的所有详细信息。
如果仍然不起作用，您可能需要通过从 /etc/postfix/main.cf 中查找 ^smtp.*sasl 参数来扩展您的问题。
答案3
我遇到了类似的问题：
SASL PLAIN authentication failed: no mechanism available
并发现缺少一个包裹：
aptitude install libsasl2-modules-sql
解决了这个问题