Not even RCPT TO can be used to verify users (Microsoft strikes again)

To: djb-qmail@xxxxxxxxxxxxxxxxxxxx
Subject: Not even RCPT TO can be used to verify users (Microsoft strikes again)
From: sthaug@xxxxxxxxxx
Date: Mon, 20 Jan 1997 10:16:25 +0100
Delivered-to: djb-qmail@xxxxxxxxxxxxxxxxxxxx

This is not really qmail-specific, but I thought I would mention it.
I found an SMTP server which apparently doesn't react sensibly to
RCPT TO commands. Have a look at the following transaction:

% host intranet.no
intranet.no mail is handled (pri=10) by server-1.intranet.no
% telnet server-1.intranet.no smtp
Trying 194.19.82.10...
Connected to server-1.intranet.no.
Escape character is '^]'.
220 server-1.intranet.no Microsoft Exchange Internet Mail Connector 4.0.837.3 ready
helo verdi.nethelp.no
250 OK
mail from: <sthaug@xxxxxxxxxx>
250 OK - mail from  <sthaug@xxxxxxxxxx>
rcpt to: <postmaster@xxxxxxxxxxx>
250 OK - Recipient <postmaster@xxxxxxxxxxx>
rcpt to: <xyzzy@xxxxxxxxxxx>
250 OK - Recipient <xyzzy@xxxxxxxxxxx>
rcpt to: <blurflblurf@xxxxxxxxxxx>
250 OK - Recipient <blurflblurf@xxxxxxxxxxx>
rcpt to: <abcdefgh@xxxxxxxxxxx>
250 OK - Recipient <abcdefgh@xxxxxxxxxxx>
rcpt to: <frobnitz@xxxxxxxxxxx>
250 OK - Recipient <frobnitz@xxxxxxxxxxx>
quit
221 closing connection

It appears that the server will say OK to *anything* given to it in
a RCPT TO command. Anybody else seen this?

Steinar Haug, Nethelp consulting, sthaug@xxxxxxxxxx

Follow-Ups:

Re: Not even RCPT TO can be used to verify users (Microsoft strikes again)

From: Keith Owens <kaos@xxxxxxxxxx>

Re: Not even RCPT TO can be used to verify users (Microsoft strikes again)

From: Christopher Samuel <chris@xxxxxxxxxxxxxxxxx>