我在我的服务器上运行 centOs，并且我使用 postfix 发送电子邮件，但是不久之前，postfix 开始退回我尝试发送的每封邮件，并出现以下错误：
Jun 9 12:06:49 IrideLamp1 postfix/pickup[20293]: 29475A24DC: uid=48 from=<apache>
Jun 9 12:06:49 IrideLamp1 postfix/cleanup[21656]: 29475A24DC: message-id=<[email protected]>
Jun 9 12:06:49 IrideLamp1 postfix/qmgr[20294]: 29475A24DC: from=<[email protected]>, size=765, nrcpt=1 (queue active)
Jun 9 12:06:49 IrideLamp1 postfix/smtp[21658]: 29475A24DC: to=<[email protected]>, relay=mx.irideprogetti.it[62.149.128.160]:25, delay=0.23, delays=0.05/0.01/0.06/0.11, dsn=5.1.0, status=bounced (host mx.irideprogetti.it[62.149.128.160] said: 550 5.1.0 4a6w1t00p1oDpDh01a6wKF dominio non valido / invalid domain (in reply to MAIL FROM command))
Jun 9 12:06:49 IrideLamp1 postfix/cleanup[21656]: 63DAAA24DF: message-id=<[email protected]>
Jun 9 12:06:49 IrideLamp1 postfix/qmgr[20294]: 63DAAA24DF: from=<>, size=2845, nrcpt=1 (queue active)
Jun 9 12:06:49 IrideLamp1 postfix/bounce[21660]: 29475A24DC: sender non-delivery notification: 63DAAA24DF
Jun 9 12:06:49 IrideLamp1 postfix/qmgr[20294]: 29475A24DC: removed
Jun 9 12:06:49 IrideLamp1 postfix/local[21661]: 63DAAA24DF: to=<[email protected]>, orig_to=<[email protected]>, relay=local, delay=0.03, delays=0.01/0.01/0/0.02, dsn=2.0.0, status=sent (delivered to mailbox)
Jun 9 12:06:49 IrideLamp1 postfix/qmgr[20294]: 63DAAA24DF: removed
You have new mail in /var/spool/mail/root
我怀疑这是邮件日志中提到的 dns/mx 记录问题，但我不知道如何解决这个问题。提前致谢
更新：这是我的 main.cf postfix 文件：
soft_bounce = no
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
#default_privs = nobody
#myhostname = host.domain.tld
#myhostname = virtual.domain.tld
#mydomain =
#myorigin = $myhostname
#myorigin = $mydomain
#inet_interfaces = $myhostname
#inet_interfaces = $myhostname, localhost
#inet_interfaces = localhost
inet_protocols = all
#proxy_interfaces =
#proxy_interfaces = 1.2.3.4
#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
#mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain,
# mail.$mydomain, www.$mydomain, ftp.$mydomain
unknown_local_recipient_reject_code = 550
#mynetworks_style = class
#mynetworks_style = subnet
mynetworks_style = host
#mynetworks = 168.100.189.0/28, 127.0.0.0/8
#mynetworks = $config_directory/mynetworks
#mynetworks = hash:/etc/postfix/network_table
#relay_domains = $mydestination
#relayhost = $mydomain
#relayhost = [gateway.my.domain]
#relayhost = [mailserver.isp.tld]
#relayhost = uucphost
#relayhost = [an.ip.add.ress]
#relay_recipient_maps = hash:/etc/postfix/relay_recipients
#in_flow_delay = 1s
#alias_maps = dbm:/etc/aliases
alias_maps = hash:/etc/aliases
#alias_maps = hash:/etc/aliases, nis:mail.aliases
#alias_maps = netinfo:/aliases
#alias_database = dbm:/etc/aliases
#alias_database = dbm:/etc/mail/aliases
alias_database = hash:/etc/aliases
#alias_database = hash:/etc/aliases, hash:/opt/majordomo/aliases
recipient_delimiter = +
#home_mailbox = Mailbox
#home_mailbox = Maildir/
#mail_spool_directory = /var/mail
#mail_spool_directory = /var/spool/mail
#mailbox_command = /some/where/procmail
#mailbox_command = /some/where/procmail -a "$EXTENSION"
#mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp
local_destination_recipient_limit = 300
local_destination_concurrency_limit = 5
#mailbox_transport = cyrus
#fallback_transport = lmtp:unix:/var/lib/imap/socket/lmtp
#fallback_transport =
#luser_relay = [email protected]
#luser_relay = [email protected]
#luser_relay = admin+$local
header_checks = regexp:/etc/postfix/header_checks
#fast_flush_domains = $relay_domains
smtpd_banner = $myhostname ESMTP $mail_name
#smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)
#local_destination_concurrency_limit = 2
#default_destination_concurrency_limit = 20
debug_peer_level = 2
#debug_peer_list = 127.0.0.1
#debug_peer_list = some.domain
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.6.6/samples
readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
smtp_sasl_security_options = noanonymous
smtp_sasl_local_domain =
broken_sasl_auth_clients = yes
smtp_helo_required = yes
smtp_transport = relay