我有一台使用 Postfix 作为邮件系统的服务器。我遇到的问题是我无法发送或接收电子邮件。如果我发送电子邮件，我会收到服务器的即时回复，其中显示：
Subject: test
Sent: 16/05/2011 19:08
The following recipient(s) could not be reached:
'myemail@mydomain.com' on 16/05/2011 19:08
452 4.3.1 Insufficient system storage
我已检查以下内容：
磁盘空间，所有分区上都有千兆字节的可用空间。邮箱配额，任何邮箱都没有设置配额。
我清除了所有邮件日志并重新启动了服务器，但我仍然无法发送电子邮件。有没有人有任何指示供我下一步看。
我查看了该main.cf文件，结果如下：
virtual_mailbox_domains = $virtual_mailbox_maps, hash:/var/spool/postfix/plesk/virtual_domains
virtual_alias_maps = $virtual_maps, hash:/var/spool/postfix/plesk/virtual
virtual_mailbox_maps = hash:/var/spool/postfix/plesk/vmailbox
transport_maps = hash:/var/spool/postfix/plesk/transport
smtpd_tls_cert_file = /etc/postfix/postfix_default.pem
smtpd_tls_key_file = $smtpd_tls_cert_file
smtpd_tls_security_level = may
smtpd_use_tls = yes
smtp_tls_security_level = may
smtp_use_tls = no
smtpd_sender_restrictions = check_sender_access hash:/var/spool/postfix/plesk/blacklists, permit_sasl_authenticated, check_client_access pcre:/var/spool/postfix/plesk/non_auth.re
smtp_send_xforward_command = yes
smtpd_authorized_xforward_hosts = 127.0.0.0/8
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = …