Number of Connectors

Each Internet Mail Service can accept multiple incoming connections and initiate multiple outbound connections. If you expect heavy message traffic, consider using multiple Internet Mail Services in your site and organization. In addition, you can configure specific Internet Mail Services to:

• Only accept messages.
• Only send messages.
• Receive and send messages.
• Forward all mail to relay hosts for final delivery.
• Send mail to final destinations, using DNS.

If your site has a single Internet Mail Service, you will most likely configure it as both a server and a client, so it can send messages to and receive messages from connected SMTP hosts. If your site has more than one Internet Mail Service, you can configure one or more Internet Mail Services to handle only incoming messages and other Internet Mail Services to handle only outgoing messages.

More About SMTP Addresses and Using Multiple Connectors You should also consider SMTP addresses when planning how many Internet Mail Services to set up, and where they should be placed. The default SMTP domain name used for Microsoft Exchange Server is based on the organization and site name. For example, Ferguson and Bardell's FAB organization name and NAmerica-W site name are used to generate the following default domain name: namerica-w.fab.com This domain name is appended to the user name to generate an SMTP e-mail address for messages sent through the Internet Mail Service in this site. For example, a user named Fran Wilson sending an SMTP message from this site has the following SMTP address: franwilson@namerica-w.fab.com You may want to install more than one Internet Mail Service in your organization to reflect the correct site locations, or you may want to use the same SMTP e-mail domain on all sites to avoid exposing your internal messaging topology. For information about changing the site address, see Microsoft Exchange Server Operations.