Plusnet mail server blacklisted?

[#1]

We're getting email rejections from Outlook.com when sending from our Plusnet account to a Hotmail address. Error reads: 

A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server 65.54.188.126 responded with: ** XXXXXXX@hotmail.com 550:SC-002 (BAY004-MC4F2) Unfortunately, messages from 84.93.230.250 weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. This message was created automatically by mail delivery software on the server avasout05.

(Hotmail address XXXXX'd out for privacy)

84.93.230.250 is avasout05.plus.net, so it looks like one of Plusnet's mailservers is blacklisted. We got a similar bounceback from a btinternet.com email address over the weekend. Anyone else getting problems? I can't see anything about this on the service status pages.

[#2]

It's not just you.  I can send mail to a live.com address if I use webmail but if I use my desktop client to the same address I get the following bounce:

A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server 104.47.34.33 responded with: **[email address removed] Unfortunately, messages from [84.93.230.250] weren't sent. Please contact your Internet service provider since part of their network is on our block list (AS3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. This message was created automatically by mail delivery software on the server avasout05.

Anyone from Plusnet listening?

stuck

[#3]

I suspect we'll need to contact Microsoft to request delisting.

The server in question, isn't listed on any of the typical blacklists, and its senderscore is good.

Edit: @stuck, forgot to mention: you probably had success via Webmail because you hit a different outbound server (we have quite a few of them and I doubt they're all listed).

[#4]

OK, I await further feedback.  Meanwhile, I get the same effect when sending to an outlook.com address, i.e. can send to it by webmail but not from my desktop client but a message to my work address (a .co.uk address) sent from my desktop client went without a problem.

I guess this an 'unexpected side effect' of yesterday's big outlook.com outage.

stuck

[#5]

Oh, and messages to gmail seem to be fine too.

stuck

[#6]

I don't think it's anything to do with the Outlook outage. We're not blacklisted on their O365 platform.
I've now raised a support request with Microsoft (ref: 1398757264).

[#7]

We too are getting emails repeatedly blocked when trying to deliver to the following ISP (I think):

        rhea.easily.co.uk → 185.26.230.85 ISP:NetNames Operations Limited

When I check for black listing I notice:

        http://www.anti-abuse.org/multi-rbl-check-results/?host=avasin16.plus.net&validLookup=true

       http://www.anti-abuse.org/multi-rbl-check-results/?host=avasout03.plus.net&validLookup=true

both show that avasin16.plus.net and avasout03.plus.net(added later this morning) are both being blocked by dnsbl.sorbs.net.  See attached .png for screenshot. 

Could this be the reason?

The PLusNet response to the 550:fail-deliver message says:

        A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server 185.26.230.85 responded with: ***@*.me.uk 550:behaviour. This message was created automatically by mail delivery software on the server avasout03.

The return message source says:

        Delivery-date: Tue, 19 Sep 2017 20:23:22 +0100
Received: from [212.159.9.108] (helo=avasin16.plus.net)
      by inmx02.plus.net with esmtp (PlusNet MXCore v2.00) id 1duO78-0008P0-RD
      for *@*.plus.com; Tue, 19 Sep 2017 20:23:22 +0100
Received: from avasout03.plus.net ([212.159.9.108])
    by Plusnet Cloudmark Gateway with SMTP

[#8]

My machine is OK today.  Does that mean the support request you raised yesterday has been actioned or is it just that today's connection to Plusnet is using a non-blacklised outbound server?

stuck

[#9]

Can confirm no bounces this morning. Let's hope it lasts.

[#10]

Happy to hear this appears to be sorted now.

[#11]

Yep, should be sorted now. I received this from Microsoft earlier:

As previously mentioned we detected suspicious/abusive email sending behavior from IP (84.93.230.250) due to the large difference in RCPT to commands versus emails sent. Thank you for taking the time to investigate the issue on your end. Based on the results of our investigation we have determined that this block can now be lifted. Please allow 24-48 hours for the mitigation to take effect.

[#12]

Thank you, it is still OK today so hopefully that's it - until the next time grin

[#13]

I think it has reared it's head again. I can send to gmail, my wife's work address etc but not to hotmail.com or hotmail.co.uk. I get the following error message:

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:

  xxxxxxxxx@hotmail.co.uk

    host eur.olc.protection.outlook.com [104.47.0.33]

    SMTP error from remote mail server after pipelined MAIL FROM:<jtolland@aeido.co.uk> SIZE=4983:

    550 5.7.1 Unfortunately, messages from [77.72.1.162] weren't sent. Please contact your Internet service provider since part of their network is on our block list (AS3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [HE1EUR01FT046.eop-EUR01.prod.protection.outlook.com]

Any chance you can prod Microsoft again? Thanks

[#14]

SMTP host 77.72.1.162 which is mentioned in that error message is zeus.krystal.co.uk and not one of the Plusnet relays. Hence I'd expect it to be down to Krystal Hosting to contact Microsoft to get this problem fixed.

[#15]

Thanks spraxyt, I'll get onto them.