Exactly. Now, the question remains: Can the same thing be done with
Exchange's IMS? From RFC 821:
The second step in the procedure is the RCPT command.
RCPT <SP> TO:<forward-path> <CRLF>
This command gives a forward-path identifying one recipient.
If accepted, the receiver-SMTP returns a 250 OK reply, and
stores the forward-path. If the recipient is unknown the
receiver-SMTP returns a 550 Failure reply. This second step
of the procedure can be repeated any number of times.
I'm just looking for ways to stop inbound email for unknown accounts. It
will help with spam but does not solve it because all I'm doing to rejecting
invalid addresses. It will help spam directed at unknown accounts though
and the NDR bounces that follow. For example, someone sends spam to
[EMAIL PROTECTED] and address it from
[EMAIL PROTECTED] My server accepts the message and the MTA
later kicks out an NDR for an unknown user account, which I get a copy of.
That NDR tries to send to yahoo.com but fails and gets bounced back, which I
also get a copy of. Pointless traffic that could be stopped "at the gates"
if the IMS could identify valid user accounts.
Does E2K further separate the IMS from the rest of Exchange? My
understanding was that it uses the SMTP service that comes with Windows 2000
for Internet mail.
JR
----- Original Message -----
From: "Ed Crowley" <[EMAIL PROTECTED]>
To: "Exchange Discussions" <[EMAIL PROTECTED]>
Sent: Monday, December 03, 2001 10:16 PM
Subject: RE: Stopping bad email addresses at the gates
> Your server's SMTP virtual server or IMS communicates with the Yahoo!
> server. The Yahoo! server rejects the RCPT TO: because the recipient
> doesn't exist. No message was sent; the conversation was rejected early
on.
> Therefore your server issues the NDR.
>
> To everyone who wants to understand SMTP: Read RFCs 821 and 822 (and/or
> 2821 and 2822) and understand them. These concepts become pretty clear.
> The RFCs really aren't a that hard a read.
>
> Ed Crowley MCSE+I MVP
> Tech Consultant
> Compaq Computer
> "There are seldom good technological solutions to behavioral problems."
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Hotmail Work
> Sent: Monday, December 03, 2001 6:14 AM
> To: Exchange Discussions
> Subject: Re: Stopping bad email addresses at the gates
>
>
> While it may not be standard operations, I'm trying to bounce spam and
junk
> mail before it gets transmitted. For example, here's the message I get
back
> when you try to send to an invalid yahoo.com account:
> A mail message was not sent due to a protocol error.
> 554 delivery error: dd This user doesn't have a yahoo.com account
> ([EMAIL PROTECTED]) - mta548.mail.yahoo.com
> The message that caused this notification was:
>
> This is being sent to me from my own server, yahoo never accepted the
> message. Similar things happen with Hotmail and other ISPs. I'm looking
> for ways to keep the junk from ever arriving.
>
> JR
>
> ----- Original Message -----
> From: "Roger Seielstad" <[EMAIL PROTECTED]>
> To: "Exchange Discussions" <[EMAIL PROTECTED]>
> Sent: Friday, November 30, 2001 7:43 AM
> Subject: RE: Stopping bad email addresses at the gates
>
>
> > What do you hope to accomplish? That's how SMTP is supposed to work - if
> > you're authoritative for a domain, you need to accept all mail for that
> > domain, and then send NDRs for bad addresses. I believe that's all
covered
> > in RFC 2821 and 2822.
> >
> > ------------------------------------------------------
> > Roger D. Seielstad - MCSE MCT
> > Senior Systems Administrator
> > Peregrine Systems
> > Atlanta, GA
> > http://www.peregrine.com
> >
> >
> > > -----Original Message-----
> > > From: Jim Ross [mailto:[EMAIL PROTECTED]]
> > > Sent: Friday, November 30, 2001 8:29 AM
> > > To: Exchange Discussions
> > > Subject: Stopping bad email addresses at the gates
> > >
> > >
> > > Hello,
> > > Is there a way to bounce bad Internet messages before they
> > > get delivered?
> > > If I'm understanding the flow correctly, the IMC accepts any message
> > > coming in and hands it off to the MTA. The MTA says "I don't have a
> > > mailbox for that person" and sends back out a non-delivery
> > > announcement,
> > > and in our case also sends a copy to the postmaster for
> > > review. Can we
> > > stop those messages at the Internet connector? We are
> > > running 5.5 with a
> > > single small organization right now but will be going to E2K soon.
> > >
> > > Thank you,
> > > JR
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