Announcement

Collapse
No announcement yet.

SMTP Relay via the DMZ

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

  • SMTP Relay via the DMZ

    Hi,

    We have a issue here at work... We have a clustered Exchange 2007 server in the LAN and all outgoing mail is routed via the DMZ where we have only setup the SMTP service (also in cluster, on our main web servers).
    We have to restart quite often the SMTP service to empty the smtp queue... Otherwise some mail stay there for a while...

    On the server event log, i have a lot of error :
    Event Type: Warning
    Event Source: smtpsvc
    Event Category: None
    Event ID: 4006
    Date: 8/12/2008
    Time: 13:59:03
    User: N/A
    Computer: ComputerName
    Description:
    Message delivery to the host '194.7.31.54' failed while delivering to the remote domain 'universaltrucks.be' for the following reason: The remote server did not respond to a connection attempt.

    For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
    Data:
    0000: d2 02 04 c0 ..
    or
    Event Type: Warning
    Event Source: smtpsvc
    Event Category: None
    Event ID: 4000
    Date: 8/12/2008
    Time: 13:50:56
    User: N/A
    Computer: VRITHOF12
    Description:
    Message delivery to the remote domain 'mecaressort.be' failed for the following reason: Unable to bind to the destination server in DNS.

    For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
    Data:
    0000: d5 02 04 c0 ..

    i run smtpdiag without to much error.
    What's strange is that it is sometimes OK, sometimes not...

    Thanks, for any tips.

    nicolas

  • #2
    Re: SMTP Relay via the DMZ

    The second message - is that occurring on the Exchange servers or the servers in the DMZ?

    If it is occurring on the Exchange servers then that shouldn't be happening. If you have configured the Send Connectors to use a smart host it should be sending email straight out, without doing any DNS lookups.

    Anything scanning SMTP traffic that shouldn't be? Any SMTP scanning on the firewall?

    Simon.
    --
    Simon Butler
    Exchange MVP

    Blog: http://blog.sembee.co.uk/
    More Exchange Content: http://exchange.sembee.info/
    Exchange Resources List: http://exbpa.com/
    In the UK? Hire me: http://www.sembee.co.uk/

    Sembee is a registered trademark, used here with permission.

    Comment


    • #3
      Re: SMTP Relay via the DMZ

      Both message are from the SMTP relay in the DMZ.
      We don't scan outgoing message, only incoming.

      And as i said, the biggest issue is that the problem is partialy solve by restarting the smtp service, then it hang again (but some mail are still sent ok...)

      I don't understand...

      nicolas

      Comment


      • #4
        Re: SMTP Relay via the DMZ

        What about file level AV software? Is that scanning anything it shouldn't be.

        I work on a simple basis when diagnosing SMTP delivery problems. Whatever AV software is on the machine, it must be removed and the server rebooted to ensure that it is not the cause of the issue.

        However both of those issues are either DNS or connectivity - which firmly points the finger at once place - your ISP.

        Simon.
        --
        Simon Butler
        Exchange MVP

        Blog: http://blog.sembee.co.uk/
        More Exchange Content: http://exchange.sembee.info/
        Exchange Resources List: http://exbpa.com/
        In the UK? Hire me: http://www.sembee.co.uk/

        Sembee is a registered trademark, used here with permission.

        Comment

        Working...
        X