Resolved E-mails cannot be sent to Outlook

[Riculum]

Hello together

I've had the problem for 5 days that I can't send e-mails to Outlook addresses via my own Plesk mail server. I get the following error message:

Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [*************]
weren't sent. Please contact your Internet service provider since part of
their network is on our block list (S3150). You can also refer your
provider to Troubleshooting.
[BN8NAM11FT004.eop-nam11.prod.protection.outlook.com]
​

I have submitted a dlisting request via the Outlook page. The answer:

I do not see anything offhand with the IP***********) that would be preventing your mail from reaching our customers.
​

I did set:

• SPF is working
• DKIM is working
• DMARC is working
• Reverse DNS is working

I need a solution as soon as possible because some customers have already molden each other.

If someone would like to know the IP, please send a request via PN

 

[Riculum]

Can't anybody help me?
When I checked the sending reputation of the IP, I get insufficient email seen - which means the IP has a very low email volume.

So maybe my email is not being routed as I think it is.

What can I do now?

 

[Hex]

Please contact your Internet service provider since part of
their network is on our block list (S3150). You can also refer your
provider to Troubleshooting.

From what I understand this message from outlook servers to your provider not the reverse.

 

[Hex]

What did your provider said about this?

 

[TomBoB]

Microsoft doesn't really follow other blacklists, they run their own.

Have you registered for their SNDS? Is probably the easiest way to see what's wrong. Sign in to your Microsoft account
you can also submit a request for them to look into the matter at https://support.microsoft.com/en-us/supportrequestform/8ad563e3-288e-2a61-8122-3ba03d6b8d75

Cheers, Tom

 

[Riculum]

Thank you very much for your feedback.
I registered for the program, but it seems that the transmission volume is too small, so no data is displayed. The reverse DNS was changed 1 week ago. The provider running Plesk just says that the problem is not on their side.

 

[Bitpalast]

Please send yourself an email the same way that you think you are doing it through your mail server, but send it to an address where you can receive it. Then look into the header section of the email source (not the visible header fields, but all the technical details of the way the email took through the internet). Check whether your first SMTP server is your mail server. Sometimes users only think they are sending mails through their mail server while in fact the first hop is an Internet access provider mail server. Your mail might be blocked, because that SMTP server is on the block list or a network segment the server is in.

 

[TomBoB]

Well it's a bit late, but I just read the following on The Register. Exactly like your case. You'll have to take it up with your provider and get them to clean up and get delisted with Microsoft.

Microsoft blacklisted TSO Host's email IPs from Hotmail, Outlook inboxes and no one seems to care

Cheers, Tom

 

[Riculum]

Thanks you all, I contact Outlook again and they removed my IP address from the blacklist

 

[simona6]

Hi there. We have the same.
We have over 40 domains on our server, and they don't give you any information about which domain is causing it.
We added Captcha on all forms, and prevented over email usage but still they block us without any direct detail.

It's like "my car won't work, can you fix i for me?". You need to main your car, here is a manual.
Not - "Sure, your spark plugs are not sparking correctly".

There is no means to call them.
So all our clients cannot email anyone on Outlook, AOL, Hotmail or Gmail. It's unbelievable.