Email
Postfix 正在拒絕一些傳入的電子郵件(“客戶端主機被拒絕:找不到您的主機名”)
我們的後綴有時會拒絕電子郵件。我在我們的後綴日誌(/var/log/mail.log)中看到了這個錯誤:
Feb 9 16:16:33 sd-15xxx postfix/smtpd[1972]: NOQUEUE: reject: RCPT from unknown[x.x.x.x]: 450 4.7.1 Client host rejected: cannot find your hostname, [x.x.x.x]; from=<someone@sender.com> to=<someone.else@my-domain.com> proto=ESMTP helo=<smtp.sender.com>
這是我的 postconf -n :
append_dot_mydomain = yes biff = no config_directory = /etc/postfix disable_vrfy_command = yes inet_interfaces = all mydestination = localhost, localhost.localdomain, sd-15xxx.dedibox.fr mydomain = my-domain.com myhostname = my-domain.com mynetworks = 127.0.0.0/8 192.168.0.0/24 y.y.y.y <our server IP address> relayhost = smtpd_banner = $myhostname ESMTP (Debian/GNU) smtpd_client_restrictions = reject_unknown_client, permit_mynetworks smtpd_helo_required = yes smtpd_recipient_restrictions = permit_mynetworks, reject_unauth_destination, reject_unknown_recipient_domain, reject_non_fqdn_recipient smtpd_sender_restrictions = permit_mynetworks, reject_unknown_sender_domain, warn_if_reject reject_unverified_sender virtual_alias_maps = mysql:/etc/postfix/mysql-virtual_aliases.cf,mysql:/etc/postfix/mysql-virtual_aliases_mailbox.cf virtual_gid_maps = static:5000 virtual_mailbox_base = /var/spool/vmail/ virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual_domains.cf virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual_mailboxes.cf virtual_uid_maps = static:5000
它不會經常發生,但如果我們錯過了重要的電子郵件,它可能會產生嚴重的後果。
你知道這個問題是從哪裡來的嗎?是配置問題還是反向 DNS 問題(正如我在某處讀到的那樣)?
這是 nslookup xxxx 的結果:
41.180.106.89.in-addr.arpa name = Smtp16.sender.com. Authoritative answers can be found from: 180.106.89.in-addr.arpa nameserver = dns2.iland.com. 180.106.89.in-addr.arpa nameserver = dns3.iland.com. 180.106.89.in-addr.arpa nameserver = dns1.iland.com. dns1.iland.com internet address = 65.57.248.5 dns2.iland.com internet address = 63.211.182.4 dns3.iland.com internet address = 64.154.20.10
以及 dig xxxx 的結果:
; <<>> DiG 9.5.1-P3 <<>> x.x.x.x ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 5920 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;x.x.x.x. IN A ;; AUTHORITY SECTION: . 10800 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2010020901 1800 900 604800 86400 ;; Query time: 227 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Wed Feb 10 13:45:54 2010 ;; MSG SIZE rcvd: 106
我什至不知道問題是來自我們方面還是來自發件人方面。
這是由reject_unknown_client 指令(http://www.postfix.org/postconf.5.html#reject_unknown_client_hostname)引起的
那是因為發送電子郵件的 IP 地址(在您的情況下為 xxxx)沒有返回有效的反向 dns 條目 - 要麼是因為他們的名稱伺服器上沒有提供有效主機名的 ptr 記錄,要麼是因為您的 dns 查找失敗。首先要嘗試的是“nslookup xxxx”,看看你得到了什麼。