Using port 587 for SMTP prompts for security certificate.

Discussion in 'Installation/Configuration' started by Brenton, Jul 23, 2011.

  1. Brenton

    Brenton New Member


    I'm running ISPConfig 3 on Ubuntu 10.04 and on the whole everything is perfect.

    The only issue I have is that some of my client's ISPs block port 25 and I have set up so that port 587 is also in use. It works except that everytime I send mail (using port 587) I'm prompted with the follong pop-up in Outlook:

    Internet Security Warning
    The server you are connecting to is using a security certificate that cannot be verified.

    With options to "View Cerificate", "Yes" and "No" for Do you want to continue using this server.

    This does not happen when using port 25 in my mail client.

    Is there something that I can/must set on the server?

  2. Toucan

    Toucan Member

    It's doing this because you are trying to connect over a secure connection and quite rightly, it's saying the certificate cannot be verified for that domain to ip address etc.

    On you client machine rather than sending mail through, just put in your servers ip address.

    I think that should work for you.
  3. Brenton

    Brenton New Member



    Just to follow up on my own post. This issue was driving me a little crazy and halted my migration to my new server, but this morning I woke up at 4:30 with an idea. Seems that both I and the only client who was having this problem had "Use the following type of encrypted connection:" set to "Auto". Once I set it to "None" the certificate prompt every time mail was sent disappeared.

    Sometimes it helps to sleep on a problem … for a week.

    Thanks for your reply Toucan.


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