SBS Exchange Server Sends the EHLO Command with FQDN

ID: Q228533

The information in this article applies to:

Microsoft BackOffice Small Business Server version 4.5
Microsoft BackOffice Server version 4.5
Microsoft Exchange Server, version 5.5
Microsoft Commercial Internet System versions 2.0, 2.5

SYMPTOMS

When you configure your BackOffice Small Business Server (SBS) Exchange Server computer to use Authenticated TURN (ATRN), you may be unable to receive Internet e-mail.

CAUSE

This behavior occurs because the SBS configuration of ATRN specifies a fully qualified domain name (FQDN) instead of a standard domain name configuration.

Exchange Server sends the EHLO command with the FQDN to the hosting server (for example, machinename.domain.com, where machinename is the name of your server and domain is the name of your domain).

Microsoft Commercial Internet Server (MCIS) or the Simple Mail Transfer Protocol (SMTP) service from the Microsoft Windows NT Option Pack with Microsoft Windows NT 4.0 Service Pack 4 uses the information that is passed with the EHLO command to know what domain to authenticate the user name and password against.

RESOLUTION

To enable user@domain.com (where user is the name of the user) to receive Internet e-mail (instead of user@machinename.domain.com), you may need to create two domains on the SMTP server. To do this, use the steps described in the following Microsoft Knowledge Base article:

Q194501 XFOR: How to Configure Authenticated TURN

You must use the same account and password for both domains. All domains that you configure using the same account and password are TURNed after the connection is authenticated and Exchange Server sends the TURN command.

To disable 8BITMIME support, use the steps described in the following Microsoft Knowledge Base article:

Q198415 XFOR: Disable 8-BIT MIME Support on NT Option Pack SMTP Service

Exchange Server 5.5 currently does not support 8BITMIME.

MORE INFORMATION

ATRN is an alternate for ETRN, and does not require a static IP address. Authentication is passed to the SMTP server. After authentication, the SBS Exchange Server computer sends the TURN command to the SMTP server, which causes the SMTP server to reverse the connection and forward e-mail to the IP address that the SBS Exchange Server computer currently maintains.

Additional query words: smallbiz

Keywords :
Version : winnt:2.0,2.5,4.5,5.5
Platform : winnt
Issue type : kbprb