Forum Discussion

Melman1's avatar
New Contributor II
6 years ago

Cox not receiving emails from Microsoft (,

For a message sent from a account to a list that includes multiple addresses, eventually a non-delivery notice comes back saying all the recipients were unreachable.  The message for all of them is exactly the same:

4/3/2019 6:55:08 PM - Server at returned '550 5.4.317 Message expired, cannot connect to remote server(421 cmsmtp blocked. Refer to Error Codes section at for more information. AUP#CXCNCT)'
4/3/2019 6:49:13 PM - Server at ( returned '450 4.4.317 Cannot connect to remote server [Message=421 cmsmtp too many sessions from Refer to Error Codes section at for more information. AUP#CXCNCT] [] [LastAttemptedIP=] [](421 cmsmtp too many sessions from Refer to Error Codes section at for more information. AUP#CXCNCT)'

I cannot get individual messages to my account from various and accounts.  I expect I'll get non-delivery notices for these in a day or two.

Something is broken.  How do I get this message in front of someone who can DO something?  Cox Chat and Tier 1 phone reps were typically useless.  ("What device are you using?  What is your operating system?")  THIS IS A MAIL SERVER PROBLEM.  PLEASE HELP.

11 Replies

  • EricaW's avatar
    Former Moderator
    Hi Melman1,

    Have you had the opportunity to send a message to one of the affected addresses, making it the only recipient at the time?

    Cox Support Forums Moderator
    • Melman1's avatar
      New Contributor II

      Yes Erica, I sent emails to my Cox account from every other email account that I have.  Everything was received immediately EXCEPT for messages from my Hotmail accounts.

      FYI I spoke to a Tier 2 person tonight who explained that Cox has been limiting the incoming email from the Microsoft email servers (,,  There is no estimate for when this will be resolved.  It was decided to do this because of excessively high volume of incoming messages.  I have never heard of an email provider doing this before.  But the failure to inform the users is a worse problem.  I had to work really hard to get to an answer on this.

    • Florp's avatar
      New Contributor

      Running into the same issue Melman1 is reporting; emails from an address are being blocked by cox's mail servers with code CXCNCT. Is anyone at Cox looking into this?

      • Melman1's avatar
        New Contributor II

        As of about 2 hours ago (2 PM MST Thurs April 4), messages from are coming in with no delay.  The test messages that I mentioned in my previous post were also received.

  • I started having the same issue Sunday morning.  A friend who is sending emails from Hotmail through Outlook with MSN has not been able to get an email to me all week.  As of yesterday afternoon, it appeared that some of the delayed emails were being received.  Is the issue resolved?

    • KevinM2's avatar
      Former Moderator

      Hello, can you please send us an email at, and include a link to this forum thread? We will need to obtain additional information about your account services, prior to escalating this case. -Kevin M. Cox Support Forum Moderator

      • Melman1's avatar
        New Contributor II

        KevinM2, you don't need any more data from us.  I included one of the non-delivery messages.  I told you that I talked to a Tier 2 rep who understood the problem.

        Don't you Cox people talk to each other?  YOU tell US what the status is.  We are just guessing.

        I'm sorry but I'm still really mad about how much effort I spent getting to the root of the problem.