MSU Listserv


MSUNAG Archives

MSUNAG Archives


MSUNAG@LIST.MSU.EDU


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV at MSU

LISTSERV at MSU

MSUNAG Home

MSUNAG Home

MSUNAG  March 2004

MSUNAG March 2004

Subject:

Re: Question for email gurus

From:

Doug Nelson <[log in to unmask]>

Reply-To:

Doug Nelson <[log in to unmask]>

Date:

Thu, 25 Mar 2004 10:42:40 -0500

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (130 lines)

I don't follow this.  What do you think that mail.msu.edu is doing
incorrectly?  From what I see, it is returning 250 for each RCPT
with a valid id, and 5xx for each invalid recipient line.  That is
exactly what my reading of the RFC would indicate should happen.
Given what mail.msu.edu returns, , it should be easy for the sender
to match up the failed recipients with the matching 5xx code.
It's unfortunate that some of the clients seem not to reasonably
follow the spec.

Doug


> technically, RFC 2821 states:
>
>  The first or only argument to this command includes a forward-path
>    (normally a mailbox and domain, always surrounded by "<" and ">"
>    brackets) identifying one recipient.  If accepted, the SMTP server
>    returns a 250 OK reply and stores the forward-path.  If the recipient
>    is known not to be a deliverable address, the SMTP server returns a
>    550 reply, typically with a string such as "no such user - " and the
>    mailbox name (other circumstances and reply codes are possible).
>    This step of the procedure can be repeated any number of times.
>
> However, in practice, some servers do not perform recipient
>    verification until after the message text is received.  These servers
>    SHOULD treat a failure for one or more recipients as a "subsequent
>    failure" and return a mail message as discussed in section 6.  Using
>    a "550 mailbox not found" (or equivalent) reply code after the data
>    are accepted makes it difficult or impossible for the client to
>    determine which recipients failed.
>
> (http://ftp.rfc-editor.org/in-notes/rfc2821.txt)
>
> mail.msu.edu is not doing this.  if the client is using pipelineing, it
> should accept as long as one RCPT TO address was valid.
>
> the simplest fix would be:
>
> (http://www.exim.org/exim-html-4.30/doc/html/FAQ_4.html)
>
> Q0416:
> <http://www.exim.org/exim-html-4.30/doc/html/FAQ.html#TOC155>  What is
> quickest way to set up Exim so any message sent to a non-existing user
> would bounce back with a different message, based on the name of
> non-existing user?
>
> A0416:  Place this router last, so that it catches any local addresses
> that are not otherwise handled:
>
>    non_exist:
>      driver = accept
>      transport = non_exist_reply
>      no_verify
>
> Then add the following transport to the transports section:
>
>    non_exist_reply:
>      driver = autoreply
>      user = exim
>      to = $sender_address
>      subject = User does not exist
>      text = You sent mail to $local_part. That's not a valid user here. \
>
>
>             The subject was: $subject.
>
>
> jason
>
> Ed Symanzik wrote:
>
> > /home/zik> telnet mail.msu.edu smtp
> > Trying 35.9.75.123...
> > Connected to mail.msu.edu.
> > Escape character is '^]'.
> > 220 sys23.mail.msu.edu ESMTP Exim 4.24 Wed, 24 Mar 2004 14:12:34 -0500
> > ehlo foo
> > 250-sys23.mail.msu.edu Hello hardy.cl.msu.edu [35.8.3.246]
> > 250-SIZE 52428800
> > 250-PIPELINING
> > 250-AUTH PLAIN LOGIN
> > 250-STARTTLS
> > 250 HELP
> > mail from: [log in to unmask]
> > 250 OK
> > rcpt to: [log in to unmask]
> > 550 unknown user
> > rcpt to: [log in to unmask]
> > 550 unknown user
> > rcpt to: [log in to unmask],[log in to unmask]
> > 501 [log in to unmask],[log in to unmask]: malformed address: ,[log in to unmask] may not
> > follow [log in to unmask]
> > rcpt to: [log in to unmask]
> > 250 Accepted
> > data
> > 354 Enter message, ending with "." on a line by itself
> > Subject: foo
> >
> > test
> > .
> > 250 OK id=1B6DrC-0004kF-96
> > quit
> > 221 sys23.mail.msu.edu closing connection
> > Connection closed by foreign host.
> >
> >
> >
> > This test came through ok, even though there were previous lines with
> > unknown users.  I did a similar test with Mozilla and it refuses to
> > send the message.  Looks to me like a client feature.  Not terribly
> > friendly though that it won't tell you which address failed.
> >
> > Note, this is one method of finding which address is bad.
> >
> > I believe the difference in behavior here is that Pilot would accept
> > mail for accounts that had not yet been activated.
> >
> > --
> > Ed Symanzik
> > MSU Mail Team
> > [log in to unmask]
> >
>
>



Doug Nelson, Network Manager             |  [log in to unmask]
Academic Computing and Network Services  |  Ph: (517) 353-2980
Michigan State University                |  http://www.msu.edu/~nelson/

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

December 2023
June 2023
May 2022
April 2022
March 2022
February 2022
December 2021
January 2019
August 2018
June 2018
May 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003
December 2002
November 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001

ATOM RSS1 RSS2



LIST.MSU.EDU

CataList Email List Search Powered by the LISTSERV Email List Manager