求助：sasl authentication 问题

各位好；

给公司内部配置个邮件服务器，不对外。
以文章http://linuxu.blog.51cto.com/9471357/1641436/作为参考。
目前出现这样的问题:
[root@XTIC ~]# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 XTIC ESMTP Postfix
auth login
334 VXNlcm5hbWU6

334 UGFzc3dvcmQ6

535 5.7.8 Error: authentication failed: generic failure
quit
221 2.0.0 Bye
Connection closed by foreign host.

maillog文件显示：

[root@XTIC log]# tail maillog
Sep 27 15:51:41 XTIC postfix/smtpd[30876]: connect from localhost[127.0.0.1]
Sep 27 15:52:06 XTIC postfix/smtpd[30876]: warning: SASL authentication failure: All-whitespace username.
Sep 27 15:52:06 XTIC postfix/smtpd[30876]: warning: localhost[127.0.0.1]: SASL LOGIN authentication failed: generic failure
Sep 27 15:53:42 XTIC postfix/smtpd[30876]: warning: SASL authentication failure: All-whitespace username.
Sep 27 15:53:42 XTIC postfix/smtpd[30876]: warning: localhost[127.0.0.1]: SASL PLAIN authentication failed: generic failure
Sep 27 15:53:53 XTIC postfix/smtpd[30876]: disconnect from localhost[127.0.0.1]
Sep 27 16:55:13 XTIC postfix/smtpd[31397]: connect from localhost[127.0.0.1]
Sep 27 16:55:25 XTIC postfix/smtpd[31397]: warning: SASL authentication failure: All-whitespace username.
Sep 27 16:55:25 XTIC postfix/smtpd[31397]: warning: localhost[127.0.0.1]: SASL login authentication failed: generic failure
Sep 27 16:55:29 XTIC postfix/smtpd[31397]: disconnect from localhost[127.0.0.1]

我的postfix的main.cf文件为：

readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
inet_protocols = ipv4
meta_directory = /etc/postfix
shlib_directory = no

myhostname = XTIC
mydomain = mail.xtic.com
myorigin = $mydomain
inet_interfaces = all
mynetworks = 192.168.2.0/24, 127.0.0.0/8
alias_maps = hash:/etc/aliases
smtputf8_enable = no

postfix support smtp

smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain =
smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination
broken_sasl_auth_clients = yes
smtpd_client_restrictions = permit_mynetworks,permit_sasl_authenticated
smtpd_sasl_security_options = noanonymous

postfix support virtual

virtual_mailbox_base = /var/mailbox
virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf
virtual_alias_domains =
virtual_alias_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf
virtual_uid_maps = static:2525
virtual_gid_maps = static:2525
virtual_transport = virtual

这个问题已经困扰我很久了，网上也没有什么明确的解决方案，想请教论坛上的各位大神，有谁能给点建议，谢谢！