Microsoft SMTP Server computer requirements

As part of configuring SMTP archiving, you must set up a Microsoft SMTP Server to receive a copy of each SMTP message that you want Enterprise Vault to archive.

Note the following:

Although you can install the Microsoft SMTP Server on the same computer as Enterprise Vault, it is more common to install it on a separate computer.
Enterprise Vault stores all the messages that you send to SMTP archiving; it does not perform any filtering. For this reason, only SMTP messages should be sent to the Microsoft SMTP server, and not Exchange MAPI messages. We recommend that you do not run Microsoft Exchange Server on this computer.
We recommend that you locate the holding area for the EML files locally on the Microsoft SMTP Server computer.

The following software versions are required on the Microsoft SMTP Server computer:

Windows Server 2003 with Service Pack 2 or later, or Windows Server 2008 with Service Pack 1 or later. If Windows Server 2008 with Service Pack 1 is installed, you must also install the following mandatory hotfix for IIS:

http://support.microsoft.com/kb/949516

Note that the hotfix that Microsoft provides for Windows Vista is the hotfix to use for Windows Server 2008.
IIS 6.0 or later.

You must configure a Microsoft SMTP virtual server in IIS. For more information, see the Setting up SMTP Archiving manual.