Email address on Blacklist

[#1]

I have been a Plusnet customer for 15 years and have a fixed IP address. I recently found that some emails I have been sending from @xxxxxx.plus.com have not been received. I have spoken to the company which hosts the target address and have been told that it is because plus.com domain appears on the Spamhaus ZEN blacklist. That company discards any emails which match that address, without sending a notification to the source. As my email address is considered a sub-domain of plus.com, that also gets rejected.

Is there any way round this, to avoid sub-domains being rejected?

[#2]

@waldron40  AFAIK the Spamhaus ZEN blacklist operates on IP addresses not domains and looking at their website https://www.spamhaus.org/zen/ seems to confirm that. It would seem that the company concerned are not giving you the correct reason for your mail being rejected.

Are you sending email from your own server or via the PlusNet SMTP system ( relay.plus.net ) ?

[#3]

I don't have a server of my own, so I am using standard Plusnet SMTP relay.plus.net. My emails are purely personal and not related to a business.

[#4]

In that case, I'd ask the company for more information because it doesnt' make sense what they've said.  Spamhaus ZEN does not block domains, only IP addresses. The Spamhaus DBL (https://www.spamhaus.org/faq/section/Spamhaus%20DBL) does list domains with poor reputations but plus.com isnt on it, and in any case is only advisory and should not be used to block email.

[#5]

Thank you for your reply. The company has sent me a link to mxtoolbox.com. On the SuperTool tab, I can enter my Plusnet email address (xxxxxxx.plus.com where xxxxxxx is my Plusnet Username)  to check against 95 Blacklists. The result says "We notice you are on a blacklist. Checking xxxxxxx.plus.com which resolves to xx.xxx.xxx.xxx (my own fixed IP Address)" Spamhaus ZEN is the only blacklist on which I am shown as listed. All the others show as OK.

As I said, this my own personal email address, which is used by no-one else and I have a fixed IP address.

Can you please confirm that I have my outgoing SMTP server configured correctly:

Server name: relay.plus.net
Port: 587
UserName: xxxxxxx (without 'plus.com')
Authentification method: Password, transmitted insecurely
Connection Security: None

Many thanks

[#6]

Sounds like your static ip has got on the Spamhaus PBL somehow, maybe accidentally. Check it here https://www.spamhaus.org/pbl/ if it's on,  you should be able to get it removed. Even so, the company should not be rejecting email because of that. It's a policy blacklist and only should be applied to email sent directly from that ip and not via the plusnet relay. Even then it's only advisory!

Your outgoing server is correct, although it's now possible to set security  using STARTTLS on port 587 

[#7]

Many thanks for the reply. I have to admit I am a little out of my depth here. I have followed the link you provided and entered my IP address. It says it is not listed in the SBL or the XBL. But is is listed in the PBL with a reference PBL1668775. When I click on that link it says

212.159.64.0/18 is listed on the Policy Block List (PBL)

Outbound Email Policy of Plusnet Plc for this IP range:

It is the policy of Plusnet Plc that unauthenticated email sent from this IP address should be sent out only via the designated outbound mail server allocated to Plusnet Plc customers. To find the hostname of the correct mail server to use, customers should consult the original signup documentation or contact Plusnet Plc Technical Support.

I have double checked, and I am definitely using relay.plus.net, set up as in my previous message.

There is a further link for "Removal Procedure" but that says it is for users running a mail server, which I am not.

Can you please advise further?
Thanks

[#8]

As I said above, being on that list shouldnt matter UNLESS you are sending directly from your own server, which you are not. If the company concerned is using the fact that it's on the PBL then they are using the list incorrectly, since your mail is being sent from relay.plus.net which is not on that list.

TBH I'm not sure that it's possible to request removal of individual IPs from the list since the whole range is on there. 

[#9]

It is the policy of Plusnet Plc that unauthenticated email sent from this IP address should be sent out only via the designated outbound mail server allocated to Plusnet Plc customers.

There is something not quite right here... the explanation seeks to suggest...

1. The SMTP relay connection is not authenticated, that is it is being used without user name and password.  Which email client are you using?  Some only ask for the credentials for the INBOUND server and you need to manually specify "use the same credentials as the inbound server".
2. The email is being relayed by your IP address - which is clearly incorrect.

It rather sounds as though the receiving domain has got things a bit wrong.

Are you sending your emails as name@account.plus.com or as name@yourdomain.co.uk hosted on Plusnet?

[#10]

I am using Thunderbird V. 68.9.0 (32 bit)

The Outgoing Server (SMTP) is relay.plus.net

Outgoing emails are sent from name@account.plus.com

At the time of the problem, Connection Security was None, but in line with the suggestion above, I have since changes it to STARTTLS

The receiving domain is hosted by IONOS