This message has been blocked because the HELO/EHLO domain is invalid

Question

Hi friends,
 We are using cisco ironport c170. Today we cannot send email for particular email id(domain). the error msg as below,
Diagnostic information for administrators:
Generating server: sgm.svc.com.sg
[email protected]
[182.**.**.51] #<[182.**.**.51] #5.0.0 smtp; 5.1.0 - Unknown address error 554-'5.7.1 [SPAM] This message
has been blocked because the HELO/EHLO domain is invalid.' (delivery attempts: 0)> #SMTP#
Original message headers:
X-IronPort-AV: E=Sophos;i="4.97,682,1389715200";
d="scan'208,217";a="3362301"
Received: from abcct01.abc.com ([10.**.**.33]) by
sgm.svc.com.sg with ESMTP/TLS/AES128-SHA; 19 Mar 2014 11:17:45 +0800
Received: from abcMB01.abc.com ([fe80::99bb:22a0:nnaa:25cc]) by
abcCT01.abc.com ([::1]) with mapi id 14.03.0123.003; Wed, 19 Mar
2014 11:18:13 +0800
From: "test" <[email protected]>
To: "[email protected]" <[email protected]>
Subject: Testing Email
Thread-Topic: Testing Email
Thread-Index: Ac9DIdjTsP9HUS2QTF6cZp6PKztE8g==
Date: Wed, 19 Mar 2014 03:18:12 +0000
Message-ID: <[email protected]>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [10.**.**.210]
Content-Type: multipart/alternative;
boundary="_000_1329D1768D6FBE4A90657F034B26A7E217D7ADD5abcMB01_"
MIME-Version: 1.0
Thank you.

Answer 1

The HELO/EHLO domain that your Cisco IronPort Email Security Appliance (ESA) uses is based on the hostname you configure for your delivery interface under Network -> IP Interfaces.  Please ensure that a valid hostname is configured.  This hostname should match the rDNS records for the public IP address used by your ESA.
Once addressed - you should be able to take the domain in question, and attempt to telnet port 25, and attempt the standard SMTP testing...
$ telnet mail.test.com 25
Trying XYZ.XY.124.XX...
Connected to mail.test.com.
Escape character is '^]'.
220 mail.test.com ESMTP
helo foo.com
250 mail.test.com
mail from: [email protected]
250 sender <[email protected]> ok
rcpt to: [email protected]
250 recipient <[email protected]> ok
data
354 go ahead
Subject: Test
TESTING
250 ok:  Message 8102 accepted
I hope this helps!
-Robert
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