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digitalmarkets's avatar
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Cox Mail Servers filtering SMTP connections from Cox Business users

Is there a reliable e-mail address or point of contact to discuss an issue I've been having with sending mail to Cox mail servers ( at and at from my own mail server that hosted on a Cox Business static IP?

I am tired of explaining everything and in multiple tickets and having my tickets closed and not finding any resolution whatsoever. This has been happening for years, and we just give up on trying to e-mail anyone on via our own mail server.

We have an absolutely spotless e-mail reputation according to which aggregates queries from many mail block lists. This is via searching for both our domain name and ip address.

Contacting the mail team directly doesn't seem to do anything either, since they report that their logs do not see connections from our mail server. That's because something is likely filtering SYN packets from our mail server - the first step to establishing a TCP connection. If we can't get a HELO out, there's likely not a log or anything to that respect in a mail server log.

Trying to ping the two mail servers results in zero replies.

Trying to traceroute the mail servers results in our pings getting dropped at either ( - for ( - for

I'm leaving out a lot of identifying information but I'll be happy to provide them to a cox representative. I'm looking for a knowledgeable point of contact that can definitively help me resolve this issue.

By the way, I tried the Cox Postmaster Contact Us Form listed here:

I immediately  received a "Mail System Error - Returned Mail" e-mail message that had the exact contents of my form submission, and a notice telling me to e-mail if this was an error. Since I can't contact the mail server anyway, that path is closed to me.

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  • JonathanJ's avatar
    Former Moderator

    If your still having issues this link will allow you to contact our business technical support team.

  • Thank you for the reply. I've filled out the form, and now I'm waiting for a response.

  • I received a form response that addresses internet speed. This is CLEARLY NOT an internet speed issue. Is there someone I can contact directly who will take a look at this?

  • As I mentioned above, I would like to have an e-mail contact so that I don't have to keep explaining myself to a new person, every single time I call. As you can see above, it's a pretty tricky issue that requires a lot of network knowledge to explain. Thus, I've had to spend a lot of time to make sure that the person on the other end knows what I'm referring to.

    At any rate, I've called multiple times and I've not gotten any closer to a solution. I can send you ticket numbers if you think it will help build my case.

  • Any e-mail contact, of course, should probably have an e-mail address that ends with "". It is impossible to deliver e-mail to "" addresses because of the issue stated above.

  • Hello,

    If are still in need to discuss these concerns regarding your business account. Please reach us on Twitter at @CoxHelp, visit us on Facebook, or email by at Provide us the name on the account with the full service address with a link to this thread, and we can contact our business partners to contact you directly.