Forum Discussion

jill_r_'s avatar
New Contributor
3 years ago

SMTP error using New Outlook

When is Cox going to upgrade their platform to solve the outgoing email sending error that happens with the new Outlook???

The only way I can send an outgoing email is to exit Outlook and log in to webmail. Your support desk confirmed that Cox is not yet updated to work with the new version of Outlook. VERY ANNOYING.

Technical details

SmtpSubmissionPermanent5XXException: Smtp submission failed. Server '' Port '465'. --> Unexpected SMTP server response. Expected: 250, actual: 503, whole response: 503 not available
Failure code: 5513

9 Replies

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  • DavidA2's avatar
    Former Moderator
    Hi Jill R.,

    I am sorry to hear that you have been having trouble with your email. I have not been made aware of any known issues that we currently have with outlook right now. I would suggest checking the outgoing server settings using the following link. .

    Cox Social Media Specialist
    • punster's avatar
      New Contributor

      This is a bs response.  I'm having the same issue now and the only response I get from cox is to use webmail.  This is bs.  

      • Darkatt's avatar
        Valued Contributor III

        Are you using outlook? Have you double checked your settings?

  • Darkatt's avatar
    Valued Contributor III

    Cox doesn't have to upgrade their system to work with the new outlook. As long as the new outlook conforms with RFC specifications for Simple Mail Transfer Protocol, (SMTP), then it will work without issue.

    Before doing the below, ensure all email sitting in the OUTBOX is deleted.

    Ensure your settings are correct, SSL, port 465, and "My Outgoing Server Requires Authentication" has to be selected. OR. Use TLS, Port 587, and again, "My Outgoing Server Requires Authentication".

    As long as your settings are correct, then it will work with Cox, since Cox's servers conform to RFC specifications. 

    • Cmkersten's avatar
      New Contributor

      Any update to this?  I'm also having this issue with the new outlook.  I've confirmed all settings are correct

      • LisaH's avatar

        Hi Cmkersten. This appears as if you may need someone to look into your account personally. We would definitely be able to assist you with this. Please reach out to us on Twitter at CoxHelp via DM, visit us on Facebook via private message, or email us at Provide us the name on the account with the complete service address with a link to this thread so we can get started. - Lisa, Cox Support Forums Moderator

    • punster's avatar
      New Contributor

      I'm wondering if this was an issue with the servers themselves as after about 48 hours it started working again.