When to create SMTP connectors in Exchange 2000 and later

There may be situations where you want to set up an SMTP connector. This article discusses the situations and requirements where you may want to consider setting up an SMTP connector.

You do not have to create an SMTP connector for the e-mail to flow in and out of the server that is running Exchange 2000 Server or Exchange Server 2003, to connect it to other servers in an Exchange organization, or to the Internet. The Exchange 2000 or Exchange 2003 virtual server handles these connections. Generally, all that you require for mail to flow is the connectivity to the Internet and an MX record that points back to the server that is running Exchange 2000 or Exchange 2003 in your organization.

If you use smart host settings on SMTP connectors or specify smart hosts on the properties of the SMTP virtual servers to try to control the flow of e-mail between servers in the same organization, this may disrupt mail flow in the organization. Only use SMTP connectors for intra-organization mail flow if you have configured the Connected Routing Groups tab to allow e-mail flow between two different routing groups and the Address Space tab is empty. Also, do not configure a smart host on an SMTP virtual server unless you only use that virtual server to send e-mail to an external system and not to send e-mail to other servers that are running Exchange 2000 and Exchange 2003 in the same organization.

If all your servers that are running Exchange 2000 and Exchange 2003 reach the Internet and successfully perform Domain Name System (DNS) lookups for Internet addresses, you may not require an SMTP connector. If they do not, and you want to designate one or a set of servers as your gateway to the Internet, you have to create an SMTP connector, and then set those servers as the source bridgehead servers of the connector.

An SMTP connector requires an SMTP virtual server. Settings on the SMTP connector override comparable settings on the virtual server. When you restrict the size of messages at the virtual server, any connector automatically inherits that limit. This behavior may be another reason to set up an SMTP connector.

Many companies have just one SMTP connector for all Internet mail. Therefore, unless you have different requirements for different domains, you will likely only configure one SMTP connector.

Reasons to create an SMTP connector include:

• You are connecting to a Microsoft Exchange Server 5.5 computer in another routing group (site), and want to use SMTP.
• You want to configure either server-side or client-side ETRN/TURN.
• You want either to send or not to send ETRN/TURN.
• You want to request ETRN/TURN when sending messages.
• You want to request ETRN/TURN from different servers.
• You want to configure outbound security, and to do it one time and affect many outbound servers.
• You want to permit high, normal, or low message priorities for a domain.
• You want to permit system or non-system messages.
• You want to schedule the SMTP connector.
• You want to use different delivery times for oversize messages.
• You want to queue mail for remote triggered delivery.
• You want to send HELO instead of EHLO.
• You want to specify a specific address space.
• You want to set delivery restrictions.