Announcement

Collapse
No announcement yet.

connection dropped due to an smtp protocol event sink (SBS2003/EX)

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • connection dropped due to an smtp protocol event sink (SBS2003/EX)

    Hello

    I am having trouble sending email to an specific domain which I am able to get MX records using NSlookup.

    -- Mail goes into the queue and retries then user gets NDR
    Could not deliver the message in the time limit specified. Please retry or contact your administrator.
    <customerdomain.com #4.4.7
    -- This message shows when clicking on the problem domain in the queue
    connection dropped due to an smtp protocol event sink

    So far I have checked or done the following

    DNS at server AND SMTP virtual Server (added new dns servers)
    Able to get MX records doing nslookup from server
    Verified email address is valid
    Created SPF record in DNSmgmt console
    Rebooted server email gone from the queue

    Have the problem ONLY with that domain

    Any ideas? Thank you in advance

  • #2
    Re: connection dropped due to an smtp protocol event sink (SBS2003/EX)

    Are the MX records for the external domain correct? Can you send mail to that domain (preferably to the same recipient) from Gmail etc?
    Gareth Howells

    BSc (Hons), MBCS, MCP, MCDST, ICCE

    Any advice is given in good faith and without warranty.

    Please give reputation points if somebody has helped you.

    "For by now I could have stretched out my hand and struck you and your people with a plague that would have wiped you off the Earth." (Exodus 9:15) - I could kill you with my thumb.

    "Everything that lives and moves will be food for you." (Genesis 9:3) - For every animal you don't eat, I'm going to eat three.

    Comment


    • #3
      Re: connection dropped due to an smtp protocol event sink (SBS2003/EX)

      If I do
      nslookup
      set q=mx
      problemdomain.com

      I can get the MX records of problemdomain.com
      I can also see in the message tracker in exchange that mail has been transfered to the problemdomain mail servers which are same ones that show
      when performin mx query. Then email comes back times out and user gets NDR. And If i look in the system manager query I see the message

      connection dropped due to an smtp protocol event sink

      Any ideas?. Thank you in advance.

      Comment


      • #4
        Re: connection dropped due to an smtp protocol event sink (SBS2003/EX)

        Well first of all, look at what the queue and NDR are telling you:

        The connection to the remote server is being made so DNS (MX record lookups) has nothing to do with your problem. This appears to be a problem at the SMTP protocol level, not a name resolution or transport problem.

        The fact that you can send email to other domains without any issue tells me that the problem is probably not on your end. Do as gforce suggested and send an email from gmail, yahoo, etc. to the problem domain and see if it is delivered. If not, then the problem is not yours and there's nothing you can do.

        If the gmail email does get delivered then I would suggest you do two things:

        1. Turn on SMTP logging on your server so that you can see the smtp commands being sent between the two servers to see what might be happening.

        2. Make a telnet connection from your Exchange server to port 25 of the problem server and try to send a test message from telnet.

        These two things will hopefully give you a clue as to what's happening.

        Comment


        • #5
          Re: connection dropped due to an smtp protocol event sink (SBS2003/EX)

          Thank you

          I was able to verify that mail was in fact transferred to the problem domain mail server so you are right problem is not on my side. I will try what you suggested. Thanks

          Comment


          • #6
            Re: connection dropped due to an smtp protocol event sink (SBS2003/EX)

            Glad you got it sorted out.

            Comment

            Working...
            X