Email forwarding service is bouncing emails

[nsihwa]

A number of emails (Outlook.com) addressed to me have not been arriving.

On checking with my DNS provider (Namesilo), I have found the following error message:

5.7.1 Unfortunately, messages from [107.170.11.17] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). 

I would be grateful if you would help me to troubleshoot this.

[mikeliuk]

Hi @nsihwa ,

A look up suggests the issue is with a mail server under emailowl.com and the company you wish to speak to about this is "Digital Ocean".

https://www.lookip.net/ip/107.170.11.17

Technical details

IP address	107.170.11.17
Address type	Public
Protocol version	IPv4
Network class	Class A
Conversions	1806306065 (decimal / iplong) 6baa0b11 (hex / base 16)
Reverse DNS	17.11.170.107.in-addr.arpa
Hostname	mx1.emailowl.com
Reverse lookup	mx1.emailowl.com
ISP	Digital Ocean
Company	Digital Ocean

[nsihwa]

Thank you.

[XRaySpeX]

@mikeliuk : Sorry, you're right! I just grabbed the wrong IP from your post & it happened to be in reverse. Shoulda kept to OP's post.

[XRaySpeX]

I really don't see why it's telling you to consult your ISP when the issue is with the sender's IP.

To get round this issue try switching your DNS provider to 1 of these public DNS pairs:

OpenDNS   :	208.67.222.222 & 208.67.220.220
Google DNS:	8.8.8.8 & 8.8.4.4 
Cloudflare DNS	1.1.1.1 & 1.0.0.1  

[mikeliuk]

The IPv4 address beginning 17 is being read backwards.

See "reverse lookup zone": https://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/configure-subnetted-reverse-...

This assumes the OP reported the original IPv4 address correctly.

[nsihwa · Accepted solution]

I solved the issue by updating my MX records, courtesy of DNS provider.