email block

My client cannot send email to message lab addresses. We do not send bulk mail and are not listed on any blacklist including Symantec.

Returned emails have a header like this:

Subject: dmcsmtp.dansmanagement.com Mail delivery failed : returning message to sender

This message was created automatically by the SMTP relay on dmcsmtp.dansmanagement.com.

A message that you sent could not be delivered to all of its recipients.

The following address(es) failed:

  coloniallifesales.com

    SMTP error from remote mail server after RCPT TO:@coloniallifesales.com>:

    host cluster9.us.messagelabs.com [52.73.243.182]:

    421 Service Temporarily Unavailable: retry timeout exceeded

------ This is a copy of the message, including all the headers. ------

Return-path: <aaraujo@dansmanagement.com>

Received: from [200.0.0.54] (port=40176 helo=dmcsmtp.dansmanagement.com)

                by dmcsmtp.dansmanagement.com with esmtp (Exim 4.82_1-5b7a7c0-XX)

                (envelope-from <aaraujo@dansmanagement.com>)

                id 1gUZwM-00008V-2X

                for <message lab client>; Wed, 05 Dec 2018 11:22:22 -0500

Received: from dmc-Mail2010.dmcdomain.local ([fe80::9c64:df94:9c18:229c]) by  dmc-Mail2010.dmcdomain.local ([fe80::9c64:df94:9c18:229c%10]) with mapi id  14.03.0415.000; Wed, 5 Dec 2018 11:22:22 -0500

X-CTCH-RefID: str=0001.0A020205.5C07FB3E.00DD,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0

From: Abigail Araujo <aaraujo@dansmanagement.com>

To: <message lab client>

Subject: Test

Thread-Topic: Test

Thread-Index: AdSMtqTriyykCgvwQCKUl+Jmuj+kSQ==

Date: Wed, 5 Dec 2018 16:22:21 +0000

Message-ID: <3C7074C5333CC54287CD83E334D3105709CD65C7@dmc-Mail2010.dmcdomain.local>

Accept-Language: en-US

Content-Language: en-US

X-MS-Has-Attach: yes

X-MS-TNEF-Correlator:

x-originating-ip: [200.0.0.152]

Content-Type: multipart/related;

                boundary="_004_3C7074C5333CC54287CD83E334D3105709CD65C7dmcMail2010dmcd_";

                type="multipart/alternative"

MIME-Version: 1.0

--_004_3C7074C5333CC54287CD83E334D3105709CD65C7dmcMail2010dmcd_

Content-Type: multipart/alternative;

                boundary="_000_3C7074C5333CC54287CD83E334D3105709CD65C7dmcMail2010dmcd_"

--_000_3C7074C5333CC54287CD83E334D3105709CD65C7dmcMail2010dmcd_

Content-Type: text/plain; charset="us-ascii"

Content-Transfer-Encoding: quoted-printable

Our email filter shows a smtp spool like this:

2018-12-09 15:01:18 cluster9.us.messagelabs.com [67.219.246.102]:25 Connection timed out
2018-12-09 15:03:25 cluster9.us.messagelabs.com [67.219.247.54]:25 Connection timed out
2018-12-09 15:05:33 cluster9.us.messagelabs.com [67.219.246.198]:25 Connection timed out
2018-12-09 15:07:40 cluster9.us.messagelabs.com [67.219.251.54]:25 Connection timed out
2018-12-09 15:09:47 cluster9.us.messagelabs.com [67.219.250.198]:25 Connection timed out
2018-12-09 15:09:47 SMTP error from remote mail server after RCPT TO:<postmaster@coloniallifesales.com>: host cluster9a.us.messagelabs.com [52.206.215.254]: 421 Service Temporarily Unavailable
2018-12-09 15:09:47 postmaster@coloniallifesales.com R=dnslookup T=remote_smtp defer (-44): SMTP error from remote mail server after RCPT TO:<postmaster@coloniallifesales.com>: host cluster9a.us.messagelabs.com [52.206.215.254]: 421 Service Temporarily Unavailable

This is my 2nd post and I have emailed the investigation email address twice. So far I have no replies