[ On Tuesday, October 28, 2003 at 15:02:14 (+1100), exim@??? wrote: ]
> Subject: RE: [Exim] Refuse connection if no MX for sending host
>
> As always, there's an exception to the rules ;) You can cheat if the
> server is NEVER going to receive mail and implement 521 reply codes
Indeed, the exception tests the rule!
Note though that "554" is the response code suggested by RFC 2821 §3.1
for the initial connection greeting response sent by servers that do not
accept any incoming e-mail but which may still wish to allow the
connection to succeed (perhaps because the host previously offered SMTP
and now wishes to notify all clients that it no longer offers that
service, or perhaps because it only accepts SMTP connections from a
"private" network and the connection must complete before the server can
identify its origin). Of course a proper SMTP client should treat any
5xx greeting response to its connection in the same way it would treat
554 and immediately bounce the message so that a human can decide what
went wrong.
--
Greg A. Woods
+1 416 218-0098 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
