My mail server www.zoong.com can receive mails for a virutal
domain sunrisevietnam.com from most of the domains.
For example, mails from Yahaoo, Hotmail, Gmail and from localhost
sent to tran@sunrisevietnam.com are received OK.

However, the server fails to receive mails from some sender domains
like eds.com, londonmet.ac.uk, freeshell.org.
The error is: 550 5.1.1 <tran@www.zoong.com>... User unknown
All the failed mails have "RCPT To:<tran@www.zoong.com>"

I ran tcpdump at the server and here is the extract from that tcpdump:

220 www.zoong.com ESMTP Sendmail 8.14.0/8.13.4; Fri, 11 May 2007 20:40:59 +1100 (VUT)


EHLO sdf.lonestar.org


250-www.zoong.com Hello mx.freeshell.ORG [192.94.73.18], pleased to meet you

250-ENHANCEDSTATUSCODES

250-PIPELINING

250-8BITMIME

250-SIZE

250-DSN

250-ETRN

250-AUTH GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN

250-DELIVERBY

250


MAIL From:<zoong@sdf.lonestar.org> SIZE=545


250 2.1.0 <zoong@sdf.lonestar.org>... Sender ok


RCPT To:<tran@www.zoong.com>

DATA


550 5.1.1 <tran@www.zoong.com>... User unknown

503 5.0.0 Need RCPT (recipient)


RSET


250 2.0.0 Reset state


QUIT


221 2.0.0 www.zoong.com closing connection


Is the problem from my mail server or from the sender's mail server?


I check all my mail server settings and don't see any problem:
# grep 'tran@sunrisevietnam' /etc/mail/genericstable
a_13745156 tran@sunrisevietnam.com
# grep 'tran@sunrisevietnam' /etc/mail/virtusertable
tran@sunrisevietnam.com a_13745156
#

The error in /var/log/maillog is like this:
/var/log/maillog_wilson:May 10 01:01:42 www sm-mta[19000]: l1ME1g4G019000: <tran@www.zoong.com>... User unknown
/var/log/maillog_wilson:Feb 12 01:02:11 www sm-mta[30670]: l1ME2BPM030670: <tran@www.zoong.com>... User unknown

I use Sendmail 8.14.0

Thanks,
Zoong

On 5/13/2007 6:53 PM, Zoong Pham wrote:
> RCPT To:<tran@www.zoong.com>

> # grep 'tran@sunrisevietnam' /etc/mail/genericstable
> a_13745156 tran@sunrisevietnam.com
> # grep 'tran@sunrisevietnam' /etc/mail/virtusertable
> tran@sunrisevietnam.com a_13745156

Um, you are dealing with two different email addresses here.

If there is something else going on I'd be happy to .



Grant. . . .

Grant,

On 2007-05-14, Grant Taylor <gtaylor@riverviewtech.net> wrote:
> On 5/13/2007 6:53 PM, Zoong Pham wrote:
>> RCPT To:<tran@www.zoong.com>
>
>> # grep 'tran@sunrisevietnam' /etc/mail/genericstable
>> a_13745156 tran@sunrisevietnam.com
>> # grep 'tran@sunrisevietnam' /etc/mail/virtusertable
>> tran@sunrisevietnam.com a_13745156
>
> Um, you are dealing with two different email addresses here.

What do you mean?

The local account is a_13745156.
Hence the local address is a_13745156@www.zoong.com

It is mapped (via /etc/mail/virtusertable) to tran@sunrisevietnam.com.

If a_13745156 sends mails out, it will appear as tran@sunrisevietnam.com.
It's done via /etc/mail/genericstable.

What I have done wrong?

The problem is, I think, the remote mail server rewrote the address tran@sunrisevietnam.com
to tran@www.zoong.com.
And of course the address tran@www.zoong.com doesn't exist.

I am not sure the remote mail server rewrote or my server rewrote the address.

Thanks,
Zoong

Zoong Pham <zoong@www.zoong.com> wrote:
>
> My mail server www.zoong.com can receive mails for a virutal
> domain sunrisevietnam.com from most of the domains.
> For example, mails from Yahaoo, Hotmail, Gmail and from localhost
> sent to tran@sunrisevietnam.com are received OK.
>
> However, the server fails to receive mails from some sender domains
> like eds.com, londonmet.ac.uk, freeshell.org.
> The error is: 550 5.1.1 <tran@www.zoong.com>... User unknown
> All the failed mails have "RCPT To:<tran@www.zoong.com>"

Don't use CNAME-RRs for mail targets, it will not work on all systems.

[doeblitz@pts/1:1117] ~ % dig sunrisevietnam.com
;; ANSWER SECTION:
sunrisevietnam.com. 1800 IN CNAME www.zoong.com.

Many system out there will replace "sunrisevietnam.com" with
"www.zoong.com" both in the SMTP dialog and the message headers. If you
use A- and MX-RRs for "sunrisevietnam.com" everything should work fine.

Ralf
--
Ralf Döblitz * Schapenstraße 6 * 38104 Braunschweig * Germany
Phone: +49-531-2361223 Fax: +49-531-2361224 mailto:doeblitz@doeblitz.net
Homepage: http://www.escape.de/users/selene/
Mit UTF-8 kann man gleichzeitig äöüßÄÖÜæœłø¼½¾¤¹²³¢€£¥¶§ ¬Ã·Ã—±©®™¡¿ verwenden…

In article <slrnf4frao.plp.zoong@www.zoong.com> Zoong Pham
<zoong@www.zoong.com> writes:
>
>The problem is, I think, the remote mail server rewrote the address
>tran@sunrisevietnam.com
>to tran@www.zoong.com.
>And of course the address tran@www.zoong.com doesn't exist.

The problem is that sunrisevietnam.com is a CNAME record in DNS (thanks
for posting real names, which makes it trivial to diagnose such issues),
i.e. DNS says that it's just an alias, and the canonical name is
www.zoong.com. Many MTAs, among them essentially all sendmail
installations, will rewrite CNAMEs to the canonical name, since the SMTP
spec used to say that CNAMEs are not allowed in e-mail addresses. If you
make sunrisevietnam.com an MX record with www.zoong.com as target, there
won't be any rewriting.

>I am not sure the remote mail server rewrote or my server rewrote the address.

Since the rewritten name was given on the RCPT command in the trace you
posted, it was probably *some* remote server that did it. However yours
would surely do it too if given the opportunity.

--Per Hedeland
per@hedeland.org

On 2007-05-14, Ralf Döblitz <doeblitz@doeblitz.net> wrote:
>
> Don't use CNAME-RRs for mail targets, it will not work on all systems.
>
> If you
> use A- and MX-RRs for "sunrisevietnam.com" everything should work fine.

Thanks guys.
I will update the DNS for the domain.

Zoong