problem sent mail prestashop

Hi!

I contact you because since 2 weeks now when a customer order on my website and choose english language I receive this message with Mail Delivery System .
This happen only with English language customer, not with French Language.
And I have problem only with the confirmation order mail, for the email like preparation or sent or Payment accept I don't have this problem.

"
A message that you sent was rejected by the local scanning code that
checks incoming messages on this system. The following error was given:

This message was classified as SPAM and may not be delivered. For more
information, please see https://www.inmotionhosting.com/support/edu/everything-email/550-spam-message

------ This is a copy of your message, including all the headers.
------ No more than 100K characters of the body are included.

Received: [email protected] by biz152.inmotionhosting.com with local (Exim 4.86_1)
(envelope-from <----------------------->)
id 1af48L-0000yl-V7
for [email protected]; Sun, 13 Mar 2016 04:24:29 -0700
To: -------------- --------------- <[email protected]>
Subject: [-----------------------] Order confirmation
X-PHP-Script: www.----------------.com/modules/paypal/express_checkout/payment.php for --.---.--.--
Return-Path: <>
From: ------------ <[email protected]>
Reply-To: [email protected]
Date: Sun, 13 Mar 2016 18:24:29 +0700
X-LibVersion: 3.3.2
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="_=_swift-43359686456e54dede10ce4.77100750_=_"
Content-Transfer-Encoding: 7bit
Message-ID: <[email protected]>

This is a message in multipart MIME format. Your mail client should not
be displaying this. Consider upgrading your mail client to view this
message correctly.
--_=_swift-43359686456e54dede10ce4.77100750_=_
Content-Type: multipart/related;
boundary="_=_swift-160493352956e54dede113d4.00420710_=_"
Content-Transfer-Encoding: 7bit


--_=_swift-160493352956e54dede113d4.00420710_=_
Content-Type: multipart/alternative;
boundary="_=_swift-19376836756e54dede119a5.28452965_=_"
Content-Transfer-Encoding: 7bit


--_=_swift-19376836756e54dede119a5.28452965_=_
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit

"


Thank you for your help
Best Regards