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Ex2007/pop3 smtp error

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  • Ex2007/pop3 smtp error


    I changed the IP of an Exchange 2007 server, and also put it with a new ISP (new external IP)

    The router is setup the same with 110/25/443/80 ports for service, but now it seems that clients sending mail on pop3 isn't working. OWA works fine, and outlook exchange works fine too, all mail in and out.

    Fails with 550 5.7.1 Client does not have permissions to send as this sender.

    There was no issue prior, and the only change was the Internal and External IP.

    Any help would be appreciated.

  • #2
    Re: Ex2007/pop3 smtp error

    POP3 is a receive protocol, not a sending protocol. Why are you still using POP3 in any way, shape or form? It's a hopelessly outdated protocol.

    Now that I've got that off my chest can you explain in more detail what the problem is? Do you have internal clients using POP3 with issues? External clients trying to connect POP3 to you?
    BSc, MCSA: Server 2008, MCSE, MCSA: Messaging, MCTS
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    • #3
      Re: Ex2007/pop3 smtp error

      I hear ya, i'd rather not use it...

      It's the not the "pop3", but the smtp when the whole send/receive process happens.

      But everything else is good, outlook clients (exchange) can send and receive email , internet mail goes in and out from Exchange to the Internet.

      It's the local 2007 exchange server, internal and external clients trying to connect get the same error. But all was good before changing the IP on the server, and the ISP.

      Firewall is good (but even with internal ip clients, it still fails)

      I'm leaning towards a receive connector issue, but the IP's all look ok in there to me... but i'm at a loss now.
      Last edited by Lan21; 16th May 2012, 23:59. Reason: more detail


      • #4
        Re: Ex2007/pop3 smtp error

        you mention that you changed the IP address of the exchange server. I suspect, the internal IP address, correct?

        Are you using the same subnet stil ?
        (ie from to or did you change it completely
        like to
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        • #5
          Re: Ex2007/pop3 smtp error

          Same subnet, changed from to, same with the DC, its 1.25 and otherwise running well.


          • #6
            Re: Ex2007/pop3 smtp error


            "client does not have permission to send as this sender"

            have you made any other changes at all.. accepted domains, recipient policies, anything ?

            it sounds like the receiveconnector is accepting the connections at least, but refusing to send as that user with that authentication.

            does this happen for all users ?
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            • #7
              Re: Ex2007/pop3 smtp error

              no other changes... happens to anyone trying to send via pop3/smtp clients.

              one of the receive connectors has the ip typed in and the other two have 'All available IPv4 addresses' setting, so I can't see why that would be the issue, but yet also seems to be.

              The adapter only has 1 ip address set in the config as well.

              I have a default (servername) / client (servername) and an internet connector.

              There are two connectors setup for port 25, one with "" and another with (use all available ipv4 address). I notice you cannot have the same ip typed into both. I'm wondering WHY is there two, and WHY is it only an issue now, IF that happens to be the issue. (I don't want to break something else.)