Emails sent to me that have bounced.

[#1]

For some time now people do sporadically tell me that emails they have sent to me have bounced resulting in some sort of error message.

I have used this Plusnet email address for 20 years or so and I have always assumed that emails sent to me do get to me.  Am I being a bit simplistic , how reliable is the Plusnet email service ?  

[#2]

Am I being a bit simplistic , how reliable is the Plusnet email service ?  

Yes and its not down to reliability of the service. It's almost certainly down to the emails being flagged as possible spam. These days , spam detection is far more intensive

If you can get a copy of the bounce message from one of the senders, it should be possible to confirm why it was bounced. If you post it here then make sure you redact any email addresses as this is a public forum.

[#3]

Thanks MisterW

Looks like you are right. Here is some bits of the delivery messages that I got from  some people who sent failed emails to me :-

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

Diagnostic information for administrators:

Generating server: CWLP123MB4155.GBSP123.PROD.OUTLOOK.COM

xxxxxxxxxxxxx@xxxxxxxxxxxxxxxx
Remote server returned '550 5.7.520 Message blocked because it contains content identified as spam. AS(4810)'

Original message headers:

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

Message not delivered There was a problem delivering your message to x@x.plus.com. See the technical details below, or try resending in a few minutes.

The response from the remote server was: 552 Spam Message Rejected ------------------------------------------ I am not sure what is the best way to play this one. I wonder how many emails I do actually lose. This must be a problem for everyone using Plusnet I suppose ?

[#4]

Its not just emails sent to Plusnet https://learn.microsoft.com/en-us/answers/questions/1205224/message-identified-as-spam-remote-server...

seems like its affecting Outlook users

[#5]

The problem is NOT the Plusnet service, but rather the content of what is being sent. Links to suspicious sites can cause an email to be bounced so as to protect users. At the other end of this matter are complaints that the spam services are not aggressive enough in that phishing emails are getting through.

[#6]

I have been unable to send emails to my plusnet address from my own email host. They have all been rejected as spam even though they only contain a subject and a couple of lines of text.

I have temporarily turned off the spam filter and everything comes through okay. Not a good solution I know !

I suspect it is not specifically plusnet but perhaps a service they use ?

[#7]

For info, Plusnet use the Cloudmark antispam service

Does your email host have SPF and/or DKIM configured for your domain ?

[#8]

Yes it does seem to have DKIM:

DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=XXXXX.com;

[#9]

If you post the bounce message ( with any personal info redacted ) we might be able to see why it was bounced

[#10]

Also check the reputation of your domain / MX here - MX Lookup Tool - Check your DNS MX Records online - MxToolbox

Also this might be useful - CSI IP Reputation Remediation Portal (cloudmark.com)

[#11]

Here is the bounced email:

From: mailer-daemon@secureserver.net

Date: 03/01/2024 17:50 (GMT+00:00)

To: master@XXXXX.com

Subject: Message Delivery Failure

      This is an automatically generated Delivery Status Notification.     

Delivery to the following recipients failed permanently:

   * peter@XXXXX.plus.com

Reason: There was an error while attempting to deliver your message with [Subject: "Matches"] to peter@XXXXX.plus.com. MTA sxb1plwbeout03.prod.sxb1.secureserver.net received this response from the destination host IP - 212.159.9.200 -  552 , 552 Spam Message Rejected
.

[#12]

I ran the MX Lookup Tool but, to be honest, I am not sure what it is telling me.

[#13]

If you send a totally blank email from this address with just "test" in the subject, does it get through?

MXTools suggest that there are some issues with that sender, but is not clear what that should cause such a fundamental failure.

Try putting your own domain name into MX tools and see if that identifies any issues.  Specifically do a black list check on the identifies MX server(s).

[#14]

I had turned off spam filtering. I have just turned it on but it might be a while before I can test again.

MX Tools shows the following problems:

dmarc     mydomain.com         No DMARC Record found
mx          mydomain.com         No DMARC Record found
blacklist   iowa.footholds.net   Blacklisted by UCEPROTECTL3
https       mydomain.com        There are errors in the certificate chain
mx          mydomain.com        DMARC Quarantine/Reject policy not enabled
dns         mydomain.com        SOA Expire Value out of recommended range

(iowa... is my isp)

Thank you for your help

[#15]

Digging into the MW Toolbox reports...

More Information About Uceprotectl3

If you are on the UCEPROTECTL2/L3, you have an IP address from your ISP that falls into a poor reputation range (i.e., the entire range of IP addresses is blocked as a result of the provider hosting spammers).

Uceprotectl3 Reports Subnets

Subnet-based Blacklists are used to reject email from entire ranges of IP Addresses, i.e. providers that are hosting companies sending spam, as well as single IP Addresses that may fall in that range of IP Address.

Uceprotectl3 Reports Shared Hosts

Host-reputation Blacklists will list either single IP Addresses that host multiple domains or entire ranges of IP Addresses from DNS &/or Email Hosts that host email for their registered domains on shared email servers. When one company sends Spam Mail or Unsolicited Bulk Email (UBE), the entire ranges can be reported as blacklisted.

Uceprotectl3 Reports Sources Of Spam

Spam-based Blacklists are those that will list either single IP Addresses or entire ranges that have actually received Spam, i.e. Unsolicited Bulk Email (UBE) in their Spamtraps from an IP-Address. This could be a result of a compromised email account, an Open Relay, or simply sending mass emails / marketing and not following best practices according to the "CAN-SPAM Act of 2003" (ref: https://en.wikipedia.org/wiki/CAN-SPAM_Act_of_2003)

Uceprotectl3 Automatically Delists Entries

This blacklist does not offer any form of manual request to delist. Your IP Address will either automatically expire from listing after a given timeframe, or after time expires from the last receipt of spam into their spamtraps from your IP Address.