请教“送达回执”与“已读回执”的原理

luluboy

本人想了解，“送达回执”与“已读回执”分别是在在那个协议中定义的SMTP吗?。

那它们的运作原理是什么的呢？

有助于今后问题解决呀。。。

谢谢各位啦。。。

[ 本帖最后由 luluboy 于 2010-12-22 00:27 编辑 ]

钉子

当然是SMTP，具体原理，就要看SMTP的标准文档了。

tdk

RCPT TO:User@Site.Domain.Com notify=success,failure

tdk

就是这个命令

luluboy

恩 感谢啦。。。
找到IETF的描述了。。。这回我知道，是哪里发出这份是否成功发送至服务器的回复了。
RFC 3461                   SMTP DSN Extension               
http://datatracker.ietf.org/doc/rfc3461/?include_text=1
Simple Mail Transfer Protocol (SMTP) Service Extension
                for Delivery Status Notifications (DSNs)
截了一段，希望对大家有用：
^_^
3. The Delivery Status Notification service extension

   An SMTP client wishing to request a DSN for a message may issue the
   EHLO command to start an SMTP session, to determine if the server
   supports any of several service extensions.  If the server responds
   with code 250 to the EHLO command, and the response includes the EHLO
   keyword DSN, then the Delivery Status Notification extension (as
   described in this memo) is supported.

   Ordinarily, when an SMTP server returns a positive (2xx) reply code
   in response to a RCPT command, it agrees to accept responsibility for
   either delivering the message to the named recipient, or sending a
   notification to the sender of the message indicating that delivery
   has failed.  However, an extended SMTP ("ESMTP") server which
   implements this service extension will accept an optional NOTIFY
   parameter with the RCPT command.  If present, the NOTIFY parameter
   alters the conditions for generation of Delivery Status Notifications
   from the default (issue notifications only on failure) specified in
   [1].  The ESMTP client may also request (via the RET parameter)
   whether the entire contents of the original message should be
   returned (as opposed to just the headers of that message), along with
   the DSN.

   In general, an ESMTP server which implements this service extension
   will propagate Delivery Status Notification requests when relaying
   mail to other SMTP-based MTAs which also support this extension, and
   make a "best effort" to ensure that such requests are honored when
   messages are passed into other environments.

   In order for Delivery Status Notifications to be meaningful to the
   sender, ESMTP servers, which support this extension, should propagate
   the following information for use in generating DSNs to any other
   MTAs that are used to relay the message:

   (a)  for each recipient, a copy of the original recipient address, as
        used by the sender of the message.

        This address need not be the same as the mailbox specified in
        the RCPT command.  For example, if a message was originally
        addressed to A@B.C and later forwarded to A@D.E, after such
        forwarding has taken place, the RCPT command will specify a
        mailbox of A@D.E.  However, the original recipient address
        remains A@B.C.
        Also, if the message originated from an environment which does
        not use Internet-style user@domain addresses, and was gatewayed
        into SMTP, the original recipient address will preserve the
        original form of the recipient address.

   (b)  for the entire SMTP transaction, an envelope identification
        string, which may be used by the sender to associate any
        delivery status notifications with the transaction used to send
        the original message.