Message not delivered : 553 Message filtered

Hello,

It looks like some of our employees have trouble to send mails from our domain to Symantec customers.Our provider uses two mail servers (mx1.saas.lu and mx2.saas.lu) which are not blacklisted on the known listings.

The user forwarded me the following message:

Diagnostic information for administrators:
Generating server: mx1.saas.luxxxxx.xxxxx@xxxxxx.com
cluster5.eu.messagelabs.com #<cluster5.eu.messagelabs.com #5.1.0 SMTP; 553-Message filtered. Refer to the Troubleshooting page at> #SMTP# xxxxx.xxxxx@xxxxxx.com cluster5.eu.messagelabs.com #<cluster5.eu.messagelabs.com #5.1.0 SMTP; 553-Message filtered. Refer to the Troubleshooting page at> #SMTP# Original message headers:

Return-Path: <prvs=14691e541b=Our.Employee@luxconnect.lu>

Received: from L1VWPIEXCLCO01.luxconnect.int ([10.16.25.12]) by mx1.saas.lu

(8.14.7/8.14.7) with ESMTP id v9N89O6O007756 (version=TLSv1/SSLv3

cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL);    Mon, 23 Oct 2017 10:09:24

+0200

Received: from L1VWPIEXCLCO01.luxconnect.int ([172.22.106.12]) by

L1VWPIEXCLCO01.luxconnect.int ([172.22.106.12]) with mapi id 14.03.0195.001;

Mon, 23 Oct 2017 10:09:23 +0200

From: Our Employee <Our.Employee@luxconnect.lu>

To: 'xxxxx.xxxxx@xxxxxx.com'<xxxxx.xxxxx@xxxxxx.com>,'yyyyyy.yyyyyy@yyyyyy.com'<yyyyyy.yyyyyy@yyyyyy.com>

Subject: LuxConnect multi-tier co-location data centres, update

Thread-Topic: LuxConnect multi-tier co-location data centres, update

Thread-Index: AQHTS9XDraezt12LAE6t4owheuOrtA==

Disposition-Notification-To: Our Employee <Our.Employee@luxconnect.lu>

Return-Receipt-To: <Our.Employee@luxconnect.lu>

Date: Mon, 23 Oct 2017 08:09:22 +0000

Message-ID: <7C02B0B966545E42B7582C7224CCD6C3C38CFB31@L1VWPIEXCLCO01.luxconnect.int>

Accept-Language: en-GB, en-US

Content-Language: en-GB

X-MS-Has-Attach:

X-MS-TNEF-Correlator:

x-originating-ip: [192.168.235.51]

Content-Type: multipart/alternative;

        boundary='_000_7C02B0B966545E42B7582C7224CCD6C3C38CFB31L1VWPIEXCLCO01l_'

MIME-Version: 1.0

x-msw-jemd-newsletter: false

Could you please tell me why we are filtered and what we can do to pass through your filters. Do you need any further information to investigate?

I've already send the same informations to investigation@review.symantec.com on the 26 of October but I didnr' get any answer untill now.

Thanks,

Gilles