Transport rules will have a strong effect on communication in your organization. You must consider how they affect the client application and the users that rely on the client application. An administrator can choose to create a rule that prevents communication between various departments in an organization.
In some cases, the administrator must create a rule to meet legal or other requirements. However, some rules are in place simply because of company needs or requirements. For example, an organization could have two groups working competitively on a project and want to keep them from exchanging e-mail. The “Working with the organization-level Hub Transport” section of Chapter 3 provides details on how transport rules fit in the scheme of the Hub Transport server. The following steps describe how to create a new transport rule:
1. Select the Organization Configuration\Hub Transport folder. Click the Transport Rules tab.
Exchange Server doesn’t come with any transport rules configured, so you won’t see any entries in the Results pane the first time you create a transport rule. Otherwise, you see all of the transport rules you created in the past.
2. Click New Transport Rule in the Actions pane.
Exchange Management Console displays the New Transport Rule dialog box shown in Figure 7-2.
Figure 7-2:
Define transport rules as needed to maintain correct mail flow.
3. In the Name field, type a name for the transport rule in the Name field.
4. (Optional) Type a comment for the transport rule.
In most cases, you want to provide a comment that explains the purpose of the transport rule. A complete comment can help avoid confusion later, especially if another administrator must discover the purpose of the rule.
5. Select or deselect Enable Rule as needed. Click Next.
The wizard presents a host of conditions, as shown in Figure 7-3. A transport rule can use as many of these conditions as needed to define the rule completely. A single condition usually won’t provide discrete message selection, and overly broad rules can prove problematic because they trap more messages than intended.
6. Scroll through the list and select a condition that matches a requirement.
The wizard places the condition in the lower window shown in Figure 7-3. Notice that the condition normally has a link associated with it.
When you click this link, you see any of a number of dialog boxes asking for additional information to define the condition. For example, when you select the From People condition, you see a link for People. Click this link and you’ll see a Select Senders dialog box, where you define the people to whom the rule applies.
Figure 7-3:
Use conditions to define the limits of a transport rule.
7. Click the link associated with the condition, provide the required information in the dialog box you see, and click OK.
8. Perform Steps 6 and 7 for as many conditions as required to define the transport rule.
9. Click Next.
The wizard displays a number of actions, as shown in Figure 7-4. The actions define how the transport rule reacts when a message meets the conditions you define. You can provide as many actions as needed to provide complete support for the rule requirements.
10. Scroll through the list and check an action that matches a requirement.
As with a condition, you see a link associated with the action. Click this link to define the action completely.
11. Click the link associated with the action, provide the required infor-mation in the dialog box you see, and click OK.
12. Perform Steps 10 and 11 for as many actions as required to describe what to do with a message meeting the transport rule conditions.
Figure 7-4:
Use actions to define what task to perform with the message.
13. Click Next.
The wizard displays a number of exceptions, as shown in Figure 7-5. You don’t have to define any exceptions. This is an optional part of the trans-port rule creation process. When you do define an exception, the exception tells Exchange Server to perform the action except when a particular condi-tion occurs. Consequently, excepcondi-tions are a negative kind of condicondi-tion.
14. (Optional) Scroll through the list and select an exception that matches a requirement. Click the link associated with the exception, provide the required information in the dialog box you see, and click OK.
Perform this step as needed for any exceptions you want to define.
15. Click Next.
You see a summary of the conditions, actions, and exceptions you defined for the rule.
16. Click New and then click Finish.
Exchange Server creates the new transport rule for you.
Rules have a priority. The first rule you create has priority 0, the second has priority 1, and so on. Exchange Server executes the rules in the order in which they appear. Consequently, the order of the transport rules is impor-tant because one rule may override another rule in some situations. To change the priority of a rule, highlight the rule in the list and click Change
Priority in the Actions pane. Type a new priority in the Change Rule Priority dialog box and click OK. Exchange Server will move the rules around as required to ensure that each rule priority is unique.
Figure 7-5:
Use exceptions to define when the transport rule doesn’t apply.