iis7 smtp 不斷發送失敗

我在通過我的 asp.net mvc 應用程序發送郵件時遇到間歇性問題。它並不總是發生，但它正在發生很多。

以下是一些錯誤：

Message delivery to the host '68.87.26.147' failed while delivering to the remote domain 'comcast.net' for the following reason: An SMTP protocol error occurred.

Message delivery to the host '207.115.11.16' failed while delivering to the remote domain 'bellsouth.net' for the following reason: An SMTP protocol error occurred.

Message delivery to the host '98.138.112.38' failed while delivering to the remote domain 'ymail.com' for the following reason: An SMTP protocol error occurred.
The SMTP verb which caused the error is 'MAIL'.  The response from the remote server is '421 4.7.1 [TS03] All messages from xxx.xxx.xxx.xxx will be permanently deferred; Retrying will NOT s'.

Message delivery to the host '64.98.36.4' failed while delivering to the remote domain 'trigasco.com' for the following reason: An SMTP protocol error occurred.
The SMTP verb which caused the error is 'HELO'.  The response from the remote server is '504 5.5.2 <WIN-OB929P97YAR>: Helo command rejected: need fully-qualified hostname
'.

Message delivery to the host '66.196.118.36' failed while delivering to the remote domain 'yahoo.com' for the following reason: An SMTP protocol error occurred.
The SMTP verb which caused the error is 'MAIL'.  The response from the remote server is '421 4.7.1 [TS03] All messages from xxx.xxx.xxx.xxx will be permanently deferred; Retrying will NOT s'.

我的 smtp 虛擬伺服器設置如下：

我已將 127.0.0.1 添加到允許列表中。我收到了一些電子郵件，可能是嘗試過的一半。

我正在使用具有公共 IP 地址的專用伺服器。它不是域的一部分。

有什麼建議麼？

這裡發生了一些事情。讓我們分解它們：

4.7.1 [TS03] All messages from xxx.xxx.xxx.xxx will be permanently deferred;

請注意，這發生在 Yahoo! 上。和 ymail - 你在他們的垃圾清單上。也許您在那裡向某人發送了垃圾郵件；也許在您向他們發送垃圾郵件之前擁有此 IP 的人，也許您的反向 DNS 表明它是 PPPOE 連接上的 IP 地址，並且由於垃圾郵件的高比率而阻止了他們。不過，這不是您的郵件伺服器的錯；所以這裡沒什麼可看的。

The SMTP verb which caused the error is 'HELO'.  The response from the remote server is '504 5.5.2 <WIN-OB929P97YAR>: Helo command rejected: need fully-qualified hostname

這是一個合理的自我解釋 - 您的郵件伺服器沒有配置 FQDN。該郵件伺服器要求您在發送郵件時說明您的身份；可能是為了讓他們可以執行反向 DNS 或其他東西來匹配您所說的與您發送的內容。

Message delivery to the host '207.115.11.16' failed while delivering to the remote domain 'bellsouth.net' for the following reason: An SMTP protocol error occurred.
Message delivery to the host '68.87.26.147' failed while delivering to the remote domain 'comcast.net' for the following reason: An SMTP protocol error occurred.

這些是您應該關注的真實內容。我會破解您的wireshark/pcap，擷取您的郵件流量，然後逐步查看發生了什麼。如果必須，請通過 telnet 重新創建。這將使您更好地了解正在發生的錯誤。也許他們是你的問題，也許他們不是。

引用自：https://serverfault.com/questions/565716