Testing for Open Relays?

From: Zane H. Healy <healyzh_at_aracnet.com>
Date: Sun May 19 13:51:17 2002

>http://www.sxlist.com/techref/inet/smtpsend.htm has a sample transcript if
>you want to try individual tests by hand. BTW, there is one shortcoming of
>the tests -- they check to see if the mail is rejected at the time of the
>SMTP exchange; some people have argued that it's OK to accept the mail so
>long as it's not delivered. Personally, I prefer not to have some spammer
>wasting my resources and I prefer the mail to be rejected at the earliest
>possible point.

Using the tests at the link above, I did have three other interesting results.

rset
250 OK
MAIL FROM:<spamtest_at_>
501 Syntax error in reverse-path
RCPT TO:<fakerelaytest_at_rr.com@>
503 Bad command sequence
data
503 Bad command sequence
rset
250 OK
MAIL FROM:<spamtest_at_zane.brouhaha.com>
RCPT TO:<rr.com!fakerelaytest>
250 <spamtest_at_zane.brouhaha.com>... Sender OK
550 <<rr.com!fakerelaytest>> ... Addressee unknown
data
503 No valid recipients preceded this
rset
250 OK
MAIL FROM:<spamtest_at_zane.brouhaha.com>
RCPT TO:<rr.com!fakerelaytest_at_250 <spamtest_at_zane.brouhaha.com>... Sender OK
zane.brouhaha.com>
550 <<rr.com!fakerelaytest_at_zane.brouhaha.com>> ... Addressee unknown
data
503 No valid recipients preceded this

It looks like TCPIP V5.1 on OpenVMS differs from the standard on how it
reacts to these as well.

                        Zane
--
| Zane H. Healy                    | UNIX Systems Administrator |
| healyzh_at_aracnet.com (primary)    | OpenVMS Enthusiast         |
|                                  | Classic Computer Collector |
+----------------------------------+----------------------------+
|     Empire of the Petal Throne and Traveller Role Playing,    |
|          PDP-10 Emulation and Zane's Computer Museum.         |
|                http://www.aracnet.com/~healyzh/               |
Received on Sun May 19 2002 - 13:51:17 BST

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