拒絕空白寄件者的信件 - Linux

最近在處理大陸郵件伺服器的問題
在LOG中發現很多這樣的訊息
Oct 16 20:34:08 mg postfix/qmgr[2639]: 9A23D605F1: from=<>, size=34438,
nrcpt=1 (queue active)
Oct 16 20:34:08 mg postfix/qmgr[2639]: 72C87605EC: removed
Oct 16 20:34:08 mg postfix/smtpd[2704]: disconnect from
unknown[220.176.150.133]
Oct 16 20:34:09 mg postfix/smtp[2711]: connect to
gmail-smtp-in.l.google.com[2a00:1450:4008:c01::1b]:25: Network is unreachable
Oct 16 20:34:49 mg postfix/smtp[2711]: 9A23D605F1: to=<[email protected]>,
relay=gmail-smtp-in.l.google.com[173.194.79.26]:25, delay=41,
delays=0/0/2.6/38, dsn=5.7.1, status=bounced (host
gmail-smtp-in.l.google.com[173.194.79.26] said: 550-5.7.1 [124.74.40.58
1] Our system has detected an unusual rate of 550-5.7.1 unsolicited mail
originating from your IP address. To protect our 550-5.7.1 users from spam,
mail sent from your IP address has been blocked. 550-5.7.1 Please visit
http://www.google.com/mail/help/bulk_mail.html to review 550 5.7.1 our Bulk
Email Senders Guidelines. vs7si56357967pbc.115 - gsmtp (in reply to end of
DATA command))
Oct 16 20:34:49 mg postfix/qmgr[2639]: 9A23D605F1: removed
稍微看了一下網路上的文件，大部分都是說 from=<> 是合乎規範的寄件者
有些退信的訊息都是這樣寄送的。
假設先不管這個問題，我就是要擋掉這樣的信件，不知道該怎麼做呢？

我先在我的mail gateway的postfix設定了
mynetworks=192.168.40.240/32
inet_interfaces = 192.168.40.244/32,127.0.0.1
40.244是mail gateway的IP
40.240 是我的mail server
然後加入
smtpd_client_restrictions = permit_mynetworks,reject
smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination
照理來說，這樣的設定會讓mail gateway只會為40.240送信才對
但是看mail log裡面，還是有很多這樣的訊息
不曉得我應該還要怎麼設定，才能避免發送這種信件呢？

--
會當凌絕頂，一覽眾山小。 —— 杜甫

--