Re: Event Log Errors

From: Gregory L. Winn (gregwinn_at_online.microsoft.com)
Date: 02/22/04 

Date: Sun, 22 Feb 2004 16:03:04 GMT

Burl,

There should be no adverse effects.

The following explains the process;

The following steps outline the process that occurs when an
                  Exchange Server 2003 or Exchange 2000 Server-based server tries to send
mail to
                  a host over the Internet:
                  

1. It performs the equivalent of an Nslookup for the MX (mail
   exchanger) record of the remote domain.

2. It opens a TCP/IP connection to port 25 of the remote host.

3. It receives a <banner> from the remote host.

4. It sends an EHLO command followed by the local domain name to the
   remote host.

5. It receives a list of supported commands from the remote host.

6. It sends a MAIL FROM command followed by the e-mail address of the
   sender.

7. It receives an acknowledgement from the remote host.

8. It sends one or more RCPT TO commands followed by one or more
   recipient e-mail address.

9. It receives one of the following acknowledgements:
                                
        - One acknowledgement after a batch of RCPT TO commands if the remote host
supports
                                                         PIPELINING.
                
                -or-
        - One acknowledgement for each recipient.

10. If the remote host advertised support for the XEXCH50 command, the
Exchange server sends the XEXCH50 command followed by the number of bytes
that it intends to
                                transfer, and then the numeral 2. For example, the following command
indicates that the Exchange
                                server intends to send 1124 bytes of data:

        "XEXCH50 1124 2"

11. It receives a "354" message from the remote host permitting it to
    send the data.

12. The Exchange server sends the number of bytes of data that it
    specified in step 10 of this process.

13. When the data has been sent, the Exchange server expects the remote
    host to immediately respond with an acknowledgement. If there is no
    more mail to send, the Exchange server sends a QUIT command.

14. The Exchange server receives an acknowledgement of the QUIT command
    from the remote host.

15. The Exchange server ends the session.

The issue described in this article occurs when the Exchange
                  server does not receive the expected acknowledgement after transmitting
the
                  data associated with the XEXCH50 command. A firewall may be configured
to block the binary large
                  object (BLOB) data that follows the XEXCH50 command.

Best Regards,

Greg Winn, MSCE

SBS Online Support Professional

Get Secure! - www.microsoft.com/security

=====================================================

When responding to posts, please "Reply to Group" via your newsreader so

that others may learn and benefit from your issue.

=====================================================

This posting is provided "AS IS" with no warranties, and confers no rights.

Relevant Pages