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JCSOS's profile

New Contributor

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4 Messages

Wed, Nov 21, 2018 4:00 PM

Comcast does not let business DHCP customers send email

(https://www.spamhaus.org/pbl/query/PBL1523068)

Let's talk about PBL1523068. If you Comcast business and pull a DHCP IP address from their 174.48.0.0/12 block, there is a VERY high chance that any email you send via YOUR IP address will never reach its destination. This is because Comcast has self-imposed a Policy Block List on all IP addresses in this range. Any receiving server that checks email sent from your IP this range against the PBL will block the email preventing it from being received by your recipient. 

This is absolutely redicious, and as far as I can tell, Comcast is violating the terms of our agreement. Can ANYONE from Comcast Business explain this? 

The only explanation I can think of is that this a racket to get you to switch to a static IP address, which benefits them financially as you're required to lease their hardware and incur an extra charge for the lease.

Responses

Official Employee

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249 Messages

3 y ago

Hi! Thanks for reaching out. I can help with the email service concern. Would you mind sending a private message with your full name, the last four digits of your account number, and a phone number linked to the account so I can help?

New Contributor

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4 Messages

3 y ago

Hi Gabe,

 

Since everything I've posted so far is public information, I'd like to keep this publically posted which is the point of the forum, so others can benefit from discussions. Can you please state why business IPs set with DHCP pulling from the range I posted have been placed *BY COMCAST* in that policy block list.

Official Employee

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225 Messages

3 y ago

I understand. We ask that you send a private message in the event your account information is required so we can protect the integrity and security of your Comcast Business Account. For the protection of the network and our customers, Comcast Business Internet blocks certain ports. If you're having issues with sending or receiving emails, it's possible you may need to set up some port rules while connected to the Comcast Business Network. If you need assistance, please private message me your full name as it's listed as the authorized person, the phone number listed on your Comcast Business Account and, the address including the city, state and, zip. Otherwise, I hope this answers your question and that you enjoy the rest of your day.

New Contributor

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4 Messages

3 y ago

I'm asking why Comcast has self-imposed their DHCP IP range which they lease addresses from to their business customers on this block list https://www.spamhaus.org/pbl/query/PBL1523068 It has nothing to do with ports, it has nothing to do with account settings. This is something very simple that you can check on your end. Let's try this simple question?

 

1) Are DHCP leases in you netblock 174.48.0.0/12 given to business customers?

 

 

New Member

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163 Messages

3 y ago

We are not blocking the IP address directly. You may consider checking blacklistings to see if the IP address has been blacklisted. If you appear on the blacklist there will be an option to submit a request to remove the IP address from the blacklist. 

New Contributor

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4 Messages

3 y ago

We are getting closer -- 

 

Yes, you are correct, comcast is not blocking anything. Please pay close attention. Comcast is providing business customers with IP addresses from DHCP ranges which are included in PBLs -- they aren't technically blacklists, but have the same net effect as a blacklist with one big drawback. We cannot appeal to be removed from it as it falls on the entire range. Our IP address is in the Spamhaus PBL1523068, please see this link:  https://www.spamhaus.org/pbl/query/PBL1523068

 

Here is their removal procedure:
Removal Procedure
Removal of IP addresses within this range from the PBL is not allowed by the netblock owner's policy.

 

Comcast is the netblock owner, it is Comcast's policy. As the IP address holder, I cannot request to be removed. This is the point of the post.  Please pay close attention as this point seems to be missed:

As a business customer, by providing the customer with an IP address in a dynamic range, those ranges will fall under these PBLs. Recipient's servers check against PBLs to remove spam, whether it is or not. Per Comcast's documentation: https://postmaster.comcast.net/avoidblocks.html Comcast submits it's DHCP ranges for inclusion in DNSBL based PBLs. 

This makes it impractical to send email from an IP address in this range. However, the only other alternative would be a static IP address which requires the customer to lease the hardware for an extra fee despite the lack of proprietary technology.  This is coming full circle to the static IP scam that Comcast runs to nickel and dime their customers. 

New Member

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163 Messages

3 y ago

I will certainly forward your feedback regarding your frustrations or concerns. If you do wish to add a static Ip to the services please reach out to us at any time. 

New Contributor

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1 Message

2 m ago

"Forward your Feedback" is Comcast for, we are not going to do anything. 

Try going to a website like php.net with one of these IP's, you can't because it's blocked.  Not just one IP, but the entire block. 

Check your ip here and you will most likely find it blocked:

https://mxtoolbox.com/blacklists.aspx

To get around this I had to use a private vpn service, and route all my traffic through it.