Connectivity and managing Your Comcast Business network
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Dirty (blacklisted) IPs issued to Comcast Business Account holders.

If you are a Comcast Business account owner, and using another POP/SMTP service to send email (i.e. not a webmail provider like gmail or hotmail, etc.) then Comcast will BLACKLIST your IP address via the Comcast policy blacklist!!!




Outbound Email Policy of Comcast for this IP range:

Email sent by Comcast subscribers using a mail program such as Outlook Express are required to send the email through Comcast. To insure your mail program is properly configured, please visit If you are a Comcast Commercial Services customer and need support, please contact



Now my business email IS beling blocked BY COMCAST, no other provider is at play here. All of our email is being bounced back from certain providers such as AOL, DUE EXCLUSIVELY TO COMCAST'S POLICY, and it is hurting my business.


So, what's the resolution here?


So far, all I've gotten from Comcast is that my business account needs to be assigned a static IP address. Or we need to use the Comcast email service, not our third party email host, to send and receive email.


However, we are already paying $1,560 annually for our Comcast business account. Adding a static IP would push this amount up to a whopping $1,820+ per year!!!!!!! Otherwise, we would need to use and be charged for, Comcast's email service to the tune of $9 per email account/address, month, EXTRA, to make for a grand total payed to Comcast in excess of three grand, annually!!!!!!




Hmmm, suddenly I believe I see the true reason for COMCAST's policy blacklist, and it apparently has little or nothing to do with spam.





BTW, I've called Comcast support upwards of 6 times about this issue during the previous few days, and 100% of the time, the technical support person did not have a clue as to what I was talking about. Rather, they insisted I should contact the blacklisting company, my email service provider, etc. when actually none of this does one bit of good when COMCAST is implementing the blacklist against their own customers.


To find out if your Comcast issued IP address is also policy blacklisted by Comcast. All you need to do is this:


1 - Go to to determine what the Comcast supplied IP address is.


2 - Then add it to the end of the following URL, fully replacing the (made up) IP address in the URL below.







Official Employee

Re: Dirty (blacklisted) IPs issued to Comcast Business Account holders.


Hi Joe7 and welcome to the business forums.


I would like to look into your email issue and this possible blacklist. Please private message me your full name, the name of your business, the full address and the phone number associated with your business account.

0 Kudos

Re: Dirty (blacklisted) IPs issued to Comcast Business Account holders.

Thanks in advance for looking into this for us. The PM has now been sent with the info you requested.


If you don't mind, I would like to keep this thread up to date with our results until the issue is way or another.

0 Kudos

Re: Dirty (blacklisted) IPs issued to Comcast Business Account holders.

Still no progress toward a solution on this.


All requested info sent. And now after several support reps have been contacted; support tickets created, and so on. Yet in spite of this, the only solution presented to us by Comcast reps is that we upgrade our Comcast account to a fixed IP, which I really do believe should never be necessary just to avoide a blanket blacklisting imposed by one's own ISP.


I no of no other ISP imposing this tactic against their own customers.


We're still using our (secure) 3rd party email provider, and all email is still bouncing from AOL, and I am sure other providers as well.


I feel particularly bad about this, because I am the one who basically talked our CEO/CFO into dropping AT&T to go with Comcast! And now several of their clients never get email we send, or any response we send back to them (e.g. as per some quote request, wholesale order changes, meeting appointments, etc.) is never received, when sending email from our office using Comcast's dynamically assinged IP address.


I suppose we should have checked the Comcast policy in this regard before establishing the business account with them.


Should Comcast inform their business customers of this policy, e.g. something like "Our policy dictates that you use Comcast email servers to send any email." I would have thought, "Okay, that's cool. We'll just stick with AT&T, or go with Frontier or something...


Any help here? Or, are we just stuck?