我的后缀服务无法启动。 这里是消息：
Job for postfix.service failed. See 'systemctl status postfix.service' and 'journalctl -xn' for details. 这里是服务状态：
postfix.service - Postfix Mail Transport Agent Loaded: loaded (/usr/lib/systemd/system/postfix.service; enabled) Active: failed (Result: timeout) since Wed 2015-11-18 16:58:32 ICT; 6min ago Process: 40961 ExecStart=/usr/sbin/postfix start (code=killed, signal=TERM) Process: 40957 ExecStartPre=/usr/libexec/postfix/chroot-update (code=exited, status=0/SUCCESS) Process: 40953 ExecStartPre=/usr/libexec/postfix/aliasesdb (code=exited, status=0/SUCCESS) Nov 18 16:58:32 cpanel.redsand.vn systemd[1]: postfix.service operation timed out. Terminating. Nov 18 16:58:32 cpanel.redsand.vn systemd[1]: Failed to start Postfix Mail Transport Agent. Nov 18 16:58:32 cpanel.redsand.vn systemd[1]: Unit postfix.service entered failed state.
这是我的configuration：
alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases broken_sasl_auth_clients = yes command_directory = /usr/sbin config_directory = /etc/postfix daemon_directory = /usr/libexec/postfix data_directory = /var/lib/postfix debug_peer_level = 2 debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin xxgdb $daemon_directory/$process_name $process_id & sleep 5 delay_warning_time = 4 disable_vrfy_command = yes dovecot_destination_recipient_limit = 1 html_directory = no inet_interfaces = all mail_owner = postfix mailq_path = /usr/bin/mailq.postfix manpage_directory = /usr/share/man message_size_limit = 20480000 mydestination = localhost.$mydomain, localhost, $mydomain mydomain = cpanel.redsand.vn myhostname = cpanel.redsand.vn mynetworks = 127.0.0.1, 113.160.170.38 newaliases_path = /usr/bin/newaliases.postfix queue_directory = /var/spool/postfix readme_directory = /usr/share/doc/postfix-2.2.2/README_FILES recipient_delimiter = + relay_domains = proxy:mysql:/etc/sentora/configs/postfix/mysql-relay_domains_maps.cf sample_directory = /usr/share/doc/postfix-2.2.2/samples sendmail_path = /usr/sbin/sendmail.postfix setgid_group = postdrop smtp_use_tls = no smtpd_banner = $myhostname ESMTP smtpd_client_restrictions = smtpd_data_restrictions = reject_unauth_pipelining smtpd_helo_required = yes smtpd_helo_restrictions = smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_recipient_domain smtpd_sasl_auth_enable = yes smtpd_sasl_local_domain = $myhostname smtpd_sasl_path = private/auth smtpd_sasl_security_options = noanonymous smtpd_sasl_type = dovecot smtpd_sender_restrictions = smtpd_use_tls = no soft_bounce = yes unknown_local_recipient_reject_code = 550 virtual_alias_maps = proxy:mysql:/etc/sentora/configs/postfix/mysql-virtual_alias_maps.cf, regexp:/etc/sentora/configs/postfix/virtual_regexp virtual_gid_maps = static:12 virtual_mailbox_base = /var/sentora/vmail virtual_mailbox_domains = proxy:mysql:/etc/sentora/configs/postfix/mysql-virtual_domains_maps.cf virtual_mailbox_maps = proxy:mysql:/etc/sentora/configs/postfix/mysql-virtual_mailbox_maps.cf virtual_minimum_uid = 991 virtual_transport = dovecot virtual_uid_maps = static:991
请帮我解决这个问题，我不知道如何解决这个问题。 非常感谢。