Attachment of 2MB refused by mx.zohomail.com

This is after sending a request for support in SD using a zipped support file of 2MB

------------------

mx.zohomail.com rejected your message to the following email addresses:

ManageEngine Support Team (servicedeskplus-support@manageengine.com)
This message is too large to send. To be able to send it, make the message smaller, for example, by removing attachments.

mx.zohomail.com gave this error:
MailPolicy violation Error delivering to mailboxes

Diagnostic information for administrators:

Generating server: Mail-StG-A.aaa.local

servicedeskplus-support@manageengine.com
mx.zohomail.com
Remote Server returned '554 5.2.3 MailPolicy violation Error delivering to mailboxes'

Original message headers:

Received: from Mail-StG-A.aaa.local (192.168.1.34) by Mail-StG-A.aaa.local
 (192.168.1.34) with Microsoft SMTP Server (TLS) id 15.0.1210.3; Mon, 17 Oct
 2016 15:54:14 +0200
Received: from Mail-StG-A.aaa.local ([fe80::eccf:356c:c521:d6d4]) by
 Mail-StG-A.aaa.local ([fe80::eccf:356c:c521:d6d4%16]) with mapi id
 15.00.1210.000; Mon, 17 Oct 2016 15:54:14 +0200
From: Massimo Marino <massimo.marino@adacap.com>
To: ManageEngine Support Team <servicedeskplus-support@manageengine.com>
Subject: Sending Notification Failed
Thread-Topic: Sending Notification Failed
Thread-Index: AQHSKH1ymg6YcnnteEyEvYcg9RnqXaCsiV6A
Date: Mon, 17 Oct 2016 13:54:14 +0000
Message-ID: <29F52D34-A5F2-476F-B97E-8886F169A3E8@adacap.com>
References: <E2E585F1-24DF-499E-8A04-9B5AC761B330@adacap.com>
In-Reply-To: <E2E585F1-24DF-499E-8A04-9B5AC761B330@adacap.com>
Accept-Language: en-US, fr-FR
Content-Language: en-US
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator:
x-mailer: Apple Mail (2.3124)
x-ms-exchange-messagesentrepresentingtype: 1
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [192.168.1.190]
Content-Type: multipart/mixed;
	boundary="_005_29F52D34A5F2476FB97E8886F169A3E8adacapcom_"
MIME-Version: 1.0

Reporting-MTA: dns;Mail-StG-A.aaa.local
Received-From-MTA: dns;Mail-StG-A.aaa.local
Arrival-Date: Mon, 17 Oct 2016 13:54:14 +0000

Final-Recipient: rfc822; servicedeskplus-support@manageengine.com
Action: failed
Status: 5.2.3
Diagnostic-Code: smtp;554 5.2.3 MailPolicy violation Error delivering to mailboxes
Remote-MTA: dns; mx.zohomail.com
X-Display-Name: ManageEngine Support Team

From: Massimo Marino <massimo.marino@adacap.com>

Subject: Sending Notification Failed

Date: 17 October 2016 at 15:54:14 CEST

To: ManageEngine Support Team <servicedeskplus-support@manageengine.com>

Attached support file

Sending notifications or replying stopped working.

Email server and connection / configuration do not report issues and at first inspection it seems with wrongly formatted SSL request.