550 Executable files are not allowed in compressed files

[Pyone]

Hello,

Due to user's requirement, I have to send automated emails with .zip file attachments to a number of clients.
It was working properly until a few days ago.
All outgoing emails with .zip file attachments which are automatically sent by PHP script are not delivered to recipients.
And I got the returning email with the error "SMTP error from remote mail server after end of data:550 Executable files are not allowed in compressed files.".

Here's is the part of the returning email ;

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  [EMAIL][email protected][/EMAIL]
  host 2374.smtp.antispamcloud.com [94.75.244.183]
  SMTP error from remote mail server after end of data:
  550 Executable files are not allowed in compressed files.

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

Return-path: <[email protected]>
Received: from user by cx1.example.net with local (Exim 4.85_1)
   (envelope-from <[email protected]>)
   id 1aqAZt-000008-QZ; Wed, 13 Apr 2016 10:30:50 +0800
To: [EMAIL][email protected][/EMAIL]
Subject: Email-subject
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="==Multipart_Boundary_x4f4b65625e5ee2220745d0c732d81cb2x"
From: Sender <[email protected]>
Reply-To: [EMAIL][email protected][/EMAIL]
Message-Id: <[email protected]>
Date: Wed, 13 Apr 2016 10:30:49 +0800
X-oryonnetworks-MailScanner-Information: Please contact the ISP for more information
X-oryonnetworks-MailScanner-ID: 1aqAZt-000008-QZ
X-oryonnetworks-MailScanner: Not scanned: please contact your Internet E-Mail Service Provider for details
X-oryonnetworks-MailScanner-SpamCheck:
X-oryonnetworks-MailScanner-From: [EMAIL][email protected][/EMAIL]
X-Spam-Status: No

This is a multi-part message in MIME format.

--==Multipart_Boundary_x4f4b65625e5ee2220745d0c732d81cb2x
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: 7bit

Please help me fix this problem.
Thanks in advance.

 

[ssfred]

Hello

From the mail header, the recipient is a gmail id and the bounce message indicates that the mail was rejected by the recipient server. As a security policy gmail blocks attachments containing executables, even though they are compressed. You may refer their KB Some file types are blocked - Gmail Help for further reference.

 

[cPanelMichael]

Hello

Yes, as mentioned, it's the recipient mail server that's blocking the message:

Some file types are blocked - Gmail Help

Thank you.