求救：postfix 测试25端口有问题

Question

请教各位大虾
我在配置postfix 作telnet localhost 25 时
Trying 218.200.15.43...
Connected to localhost.localdomain (218.200.15.43).
Escape character is '^]'.
ehlo changda.cc
在这里就不动了，没反应了
日志如下：
Oct 13 11:27:48 mail postfix/smtpd[9451]: warning: dict_nis_init: NIS domain name not set - NIS lookups disabled
Oct 13 11:27:48 mail postfix/smtpd[9451]: fatal: unsupported dictionary type: mysql
Oct 13 11:27:49 mail postfix/master[9436]: warning: process /usr/libexec/postfix/smtpd pid 9451 exit status 1
Oct 13 11:27:49 mail postfix/master[9436]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling

main.cf配置文件如下
[root@mail ~]# cat /etc/postfix/mail.cf
SE=========================#

myhostname = mail.changda.cc
mydomain = changda.cc
myorigin = $mydomain
mydestination = $myhostname localhost localhost.$mydomain
mynetworks = 218.200.15.0/24 127.0.0.0/8
inet_interfaces = all

#=====================Vritual Mailbox settings=========================#
virtual_mailbox_base = /home/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:89
virtual_gid_maps = static:89
virtual_transport = virtual
maildrop_destination_recipient_limit = 1
maildrop_destination_concurrency_limit = 1

#====================QUOTA========================#

message_size_limit = 14336000
virtual_mailbox_limit = 20971520
virtual_create_maildirsize = yes
virtual_mailbox_extended = yes
virtual_mailbox_limit_maps = mysql:/etc/postfix/mysql_virtual_mailbox_limit_maps.cf
virtual_mailbox_limit_override = yes
virtual_maildir_limit_message = Sorry, the user's maildir has overdrawn his diskspace quota,please try again later.
virtual_overquota_bounce = yes

#====================SASL========================#

broken_sasl_auth_clients = yes
smtpd_recipient_restrictions =
permit_mynetworks,
permit_sasl_authenticated,
reject_invalid_hostname,
reject_non_fqdn_hostname,
reject_unknown_sender_domain,
reject_non_fqdn_sender,
reject_non_fqdn_recipient,
reject_unknown_recipient_domain,
reject_unauth_pipelining,
reject_unauth_destination,
permit
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = $myhostname
smtpd_sasl_security_options = noanonymous
smtpd_sasl_application_name = smtpd
smtpd_banner=$myhostname ESMTP "Version not Available"

#====================OTHER========================#

readme_directory = no
sample_directory = /etc/postfix
sendmail_path = /usr/sbin/sendmail
html_directory = no
setgid_group = postdrop
command_directory = /usr/sbin
manpage_directory = /usr/local/man
daemon_directory = /usr/libexec/postfix
newaliases_path = /usr/bin/newaliases
mailq_path = /usr/bin/mailq
queue_directory = /var/spool/postfix
mail_owner = postfix

请教各位，帮帮忙吧