Knowledgebase: Mail
550 5.7.1 [CS] Message blocked
Posted by on 11 May 2014 02:39 AM

At Arvixe, we are constantly working on options which can provide better services to our clients.

Emails from all our shared servers are routed through a filtering system known as mailchannels. It filters email in real time and prevents mail server blacklisting that can be more common on shared servers by blocking sending that appears to be unsolicited  More information about mailchannels can be found in the below mentioned URL.


Mailchannels has algorithms in place which will analyze the messages and if found suspicious or unsolicited it is temporarily blocked.

In that case you would receive a bounce back message with a Mailchannels Insights URL in it.


Please make a note that when you are using mail function the bounce back message will be sent to your default email account. So ensure you check it when you find email delivery has stopped from a script.


 If mass mailing occurs you will get the following message.


550 5.7.1 [CSR] Account blocked.
Spam to non-spam mails ratio has been crossed. Hence, mails from your account are automatically blocked.  Your account may have been compromised.  


The account will then need to be secured to stop the sending. After that has been done and the sending stopped the block will be lifted in 24 hours.

If the alert is a false positive or in case you are reciving a bounce back message with the Mailchannels Insight URL in it, you can raise a ticket with support [@] to speed up the resolution.



(19 vote(s))
Not helpful

Comments (16)
25 June 2014 01:11 PM
I am getting way too many of these false positives. Many of my emails are being bounced back but I notice it happens when using my Outlook 2010 and Android. I can only successfully send emails through the webmail.

I get "550 5.7.1 [CS] Message blocked."

My Outlook is configured using:
POP3: SSL 995

I was using as my incoming and outgoing servers (which seemed to work fine until about two weeks ago). I don't know what changed but I need to get this working again especially on my mobile as I'm out of office a lot.
Michael Carr
08 July 2014 01:00 PM
Please open a support ticket, we will need to see the specific account details to determine the cause of this.
16 September 2014 02:51 AM
When sending a mail to gmail account i am getting this error.

Error Type: SMTP
Remote server ( issued an error.
hMailServer sent: .
Remote server replied: 550 5.7.1 [CS] Message blocked. To fix this, visit
Michael Carr
19 September 2014 01:35 PM
Your message was blocked for any of a wide array of reasons. you need to click the link in the message and follow the instructions provided. If you need further help after that, please open a support ticket.
Lukman Hakim
30 October 2014 12:55 AM
I get this error too, it block user registration from my site.
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 protected]
SMTP error from remote mail server after end of data:
host []:
550 5.7.1 [CS] Message blocked. To fix this, visit,ss=4,sh,re=0.000,recu=0.000,reip=0.000,cl=4,cld=1,fgs=8

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

Return-path: <[email protected]>
Received: from localhost ([::1]:45332
by with esmtpsa (TLSv1:DHE-RSA-AES256-SHA:256)
(Exim 4.82)
(envelope-from <[email protected]>)
id 1XjX2A-00010L-1W
for [email protected]; Wed, 29 Oct 2014 10:27:46 -0700
Received: from ([]) by
(Horde Framework) with HTTP; Wed, 29 Oct 2014 17:27:45 +0000
Date: Wed, 29 Oct 2014 17:27:45 +0000
Message-ID: <[email protected]>
From: [email protected]
To: [email protected]
Michael Carr
06 November 2014 10:52 AM
Your message was blocked for any of a wide array of reasons. you need to click the link in the message and follow the instructions provided. If you need further help after that, please open a support ticket.
10 December 2014 10:30 AM
I would like to know how this turned out because I have the same problem.
Michael Carr
10 December 2014 10:35 AM
Not sure I understand the question but the mail filtering is still in use. If you are getting blocked you can usually click the link in the message to remove the block.
Clandestine Claro
11 February 2015 11:34 PM
does the solution above have to be done for individual email?
Ryan C
18 March 2015 10:51 PM
This solution applies to the email account in its entirety.

11 March 2015 04:50 AM
The procedure outlined here does not apply anymore - if an email triggers the Mailchannels filter the email is blocked permanently.
An additional issue is causing many problems. If you attempt to report spam that you are receiving to the originating networks they will be blocked. It doesn't matter that they are [email protected] email addresses and even [email protected] is blocked. The result is you receive huge and growing amounts of spam and you can't do anything about it.
This aside, I do not want my email policed and controlled at all and it absolutely shouldn't be.
Ryan C
18 March 2015 10:52 PM
To avoid having your email monitored by our mail channels systems, you would need to consider an Arvixe VPS/Cloud/ or Dedicated offering. Mailchannels is a *necessary* system to ensure email deliverability in shared hosting.

Nick Rhodes
09 April 2015 03:41 PM
I have suddenly started receiving these bounce backs for no aparent reason.
if I reply including the original email content (necessary for tracking email conversations) the emails bounce back.
if I delete this in my reply the email is delivered without error.
This occurs only with one recipient company who say they are not using any such monitoring service.
The link in the bounce back email gives me no option to fill out any form or report a false positive.
Ryan C
16 April 2015 04:32 PM
Please reach out to our support department so we can get this issue corrected.

Mariela Llovera
01 May 2015 06:58 AM
Yesterday I was sending emails to contacts from my personal mail list. Today I can't send a single email -not even to my gmail account- without getting this SPAM message
What can I do? Did I lost my new personal email account?
Ryan C
11 May 2015 11:18 PM
Please reach out to our support department so we can get this issue corrected.
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