Emails to a plus.net recipient rejected with 552 Spam Message Rejected

[#1]

Hi, I'm not a Plusnet customer, but I'm trying to send to Plusnet users but getting a bounce email.

"Undelivered Mail Returned to Sender" with "<FIRSTNAME@SURNAME.plus.com >: host mx.avasin.plus.net[212.159.8.200] said: 552 Spam Message Rejected  (in reply to end of DATA command)"

I get this same error when sending to 4 different @plus.com addresses from an @sias.me.uk email address. Please could you help get my email address removed from your block list?

Thank you.

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

This is the mail system at host relay.mailchannels.net.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<FIRSTNAME@SURNAME.plus.com>: host mx.avasin.plus.net[212.159.8.200] said: 552
    Spam Message Rejected  (in reply to end of DATA command)

Reporting-MTA: dns; relay.mailchannels.net
X-Postfix-Queue-ID: 2FA2E8016A5
X-Postfix-Sender: rfc822; EMAIL@sias.me.uk 
Arrival-Date: Wed, 13 Apr 2022 09:49:30 +0000 (UTC)

Final-Recipient: rfc822; FIRSTNAME@SURNAME.plus.com
Original-Recipient: rfc822;FIRSTNAME@SURNAME.plus.com
Action: failed
Status: 5.0.0
Remote-MTA: dns; mx.avasin.plus.net
Diagnostic-Code: smtp; 552 Spam Message Rejected

[#2]

Hello Dave,

A warm welcome to the forums.  It would be a great help to staff here (shorten the response time) if you could post the signature from the headers in the return message from Plusnet's mail servers.

Plusnet uses Cloudmark for its anti-spam service.

Cloudmark gathers its "intelligence" from users marking email as SPAM.

Unfortunately too many users mark email they do not want from bulk senders as SPAM rather than taking the intelligent approach of unsubscribing from the sending mailing service.  Thereby some senders become incorrectly marked as spammers.

Hopefully with the signature made available, Plusnet should be able to profile the reason why your emails are being marked as spam.  Do they contain any links to web resources?  Have you tried sending a naked email to those Plusnet users?

[#3]

Hi Townman, thanks for the reply.

The emails being blocked are plain text only with no attachments, however previously there would have been links and attachments sent.

I can see from the header (copied below) that my email today gets a high SPAM score but it was a plain text email with only one auto-created mailto link within it. I believe that my address is getting blocked as a false positive or from a previous (incorrect) appearance on a block list and that it should now be unblocked.

Thanks again. 

Return-Path: <>
Delivered-To: EMAIL@sias.me.uk
Received: from hp282.hostpapa.com
    by hp282.hostpapa.com with LMTP
    id kGlvHtucVmI43x0AXqj0Eg
    (envelope-from <>)
    for <EMAIL@sias.me.uk>; Wed, 13 Apr 2022 10:50:19 +0100
Return-path: <>
Envelope-to: EMAIL@sias.me.uk
Delivery-date: Wed, 13 Apr 2022 10:50:19 +0100
Received: from bongo.dogwood.relay.mailchannels.net ([23.83.211.21]:7467)
    by hp282.hostpapa.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
    (Exim 4.94.2)
    id 1neZdi-008WlN-Va
    for EMAIL@sias.me.uk; Wed, 13 Apr 2022 10:50:19 +0100
Received: by relay.mailchannels.net (Postfix)
    id 85BB280165A; Wed, 13 Apr 2022 09:49:35 +0000 (UTC)
Date: Wed, 13 Apr 2022 09:49:35 +0000 (UTC)
From: MAILER-DAEMON@mailchannels.net (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
To: EMAIL@sias.me.uk
Auto-Submitted: auto-replied
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
    boundary="2FA2E8016A5.1649843375/relay.mailchannels.net"
Content-Transfer-Encoding: 8bit
Message-Id: <20220413094935.85BB280165A@relay.mailchannels.net>
X-Spam-Status: No, score=2.3
X-Spam-Score: 23
X-Spam-Bar: ++
X-Ham-Report: Spam detection software, running on the system "hp282.hostpapa.com",
    has NOT identified this incoming email as spam. The original
    message has been attached to this so you can view it or label
    similar future email. If you have any questions, see
    root\@localhost for details.
    Content analysis details: (2.3 points, 5.0 required)
    pts rule name description
    ---- ---------------------- --------------------------------------------------
    0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60%
    [score: 0.4144]
    0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was
    blocked. See
    http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block
    for more information.
    [URIs: plus.net]
    1.5 KAM_MXURI URI: URI begins with a mail exchange prefix, i.e.
    mx.[...]
    -0.0 T_SCC_BODY_TEXT_LINE No description available.
X-Spam-Flag: NO

[#4]

Hi, Thanks for the reply. My earlier message appears to have disappeared so I'm trying again...

Although previously I have sent emails with links and attachments the emails now getting blocked are all emails including plain text with no links or attachments, and with the same to other Plusnet recipients.

I can see from the headers that my email gets a high SPAM score but this is incorrect. 

Thank you for checking further into this for me.

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

Return-Path: <>
Delivered-To: contact@sias.me.uk
Received: from hp282.hostpapa.com
    by hp282.hostpapa.com with LMTP
    id kGlvHtucVmI43x0AXqj0Eg
    (envelope-from <>)
    for <contact@sias.me.uk>; Wed, 13 Apr 2022 10:50:19 +0100
Return-path: <>
Envelope-to: contact@sias.me.uk
Delivery-date: Wed, 13 Apr 2022 10:50:19 +0100
Received: from bongo.dogwood.relay.mailchannels.net ([23.83.211.21]:7467)
    by hp282.hostpapa.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
    (Exim 4.94.2)
    id 1neZdi-008WlN-Va
    for contact@sias.me.uk; Wed, 13 Apr 2022 10:50:19 +0100
Received: by relay.mailchannels.net (Postfix)
    id 85BB280165A; Wed, 13 Apr 2022 09:49:35 +0000 (UTC)
Date: Wed, 13 Apr 2022 09:49:35 +0000 (UTC)
From: MAILER-DAEMON@mailchannels.net (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
To: contact@sias.me.uk
Auto-Submitted: auto-replied
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
    boundary="2FA2E8016A5.1649843375/relay.mailchannels.net"
Content-Transfer-Encoding: 8bit
Message-Id: <20220413094935.85BB280165A@relay.mailchannels.net>
X-Spam-Status: No, score=2.3
X-Spam-Score: 23
X-Spam-Bar: ++
X-Ham-Report: Spam detection software, running on the system "hp282.hostpapa.com",
    has NOT identified this incoming email as spam. The original
    message has been attached to this so you can view it or label
    similar future email. If you have any questions, see
    root\@localhost for details.
    Content analysis details: (2.3 points, 5.0 required)
    pts rule name description
    ---- ---------------------- --------------------------------------------------
    0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60%
    [score: 0.4144]
    0.0 URIBL_BLOCKED ADMINISTRATOR NOTICE: The query to URIBL was
    blocked. See
    http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block
    for more information.
    [URIs: plus.net]
    1.5 KAM_MXURI URI: URI begins with a mail exchange prefix, i.e.
    mx.[...]
    -0.0 T_SCC_BODY_TEXT_LINE No description available.
X-Spam-Flag: NO

[#5]

Hi, clearly something in my header is preventing my message from posting, so I'll attach the header as a file.

To confirm, although previously I have emailed with links and attachments these emails are only plain text with no links, yet I can see from the header that the email is still classed (incorrectly) as SPAM.

Neither my domain or my outgoing email IP is blocked anywhere, other than seemingly with Plusnet. Your assistance getting the block removed will be much appreciated.

Headers attached.

[#6]

Hiya Dave, 

Welcome to the forum and thank for getting in touch  

I'm really sorry to hear you are experiencing this issue and I would be happy to raise it to the right team. In order to do that I would need you to PM the full header as it looks like some is missing. 

[#7]

Hi Sammy.

The previously attached Word doc does contain the entire header from the bounce email I received picked up from the email properties in Outlook.

There was also an attachment delivery report (attached here).

Is there somewhere else I should be checking for the headers?

Moderators Note: Attachment containing users personal information removed to an area where they can be seen by Plusnet staff.

[#8]

Thanks Dave, I have passed this over to out Netops team to see what we can do to help and it can take up to 5 working days. 

As soon as I hear back, I will get back to you.  

[#9]

Hiya Dave, 

Thanks for your patience, I really appreciate it. 

I have had a response from the team and they have advised that the header you have provided is the header of the bounce back message. Can you PM the header of the message that was rejected? 

[#10]

@SammyM 

One would have hoped that the bounce back message contained the Cloud mark signature which support required to identify the reason for the rejection...

[#11]

Thanks @SammyM. I've just PMed you with the sent email headers.

[#12]

Thanks a lot Dave, I've just picked that up for you and will get it passed on to our netops guys, I'll make sure we keep you posted.