Simple Mail Transfer Protocol (SMTP) has become the standard for sending mail over the Internet. The Microsoft SMTP Service that is installed with your Windows 2000 operating system supports basic SMTP delivery functions. It also provides the means for configuring your hardware for message delivery over an intranet or the Internet.
Microsoft Exchange 2000 Server expands the SMTP Service with additional features for further customizing your organization's messaging configurations. Unique delivery and security requirements can be accommodated and administrators now have more granular control over message delivery.
This section contains general background information about SMTP in Exchange 2000. A recommended SMTP deployment that utilizes a mail gateway, is also described in this section.