Managing Distribution Lists in Exchange Server 2010

Introduction

There are a lot of new features that we have waited so long for and have finally arrived in the new release of Exchange Server. These new features give users and administrators a way to use distribution lists in a more powerful and efficient way than in former versions of Exchange Server.

Static versus Dynamic Distribution Lists

At first you need to decide whether to create static or dynamic distribution lists. The members of static distribution lists are added and removed manually by the group administrators. Dynamic distribution list members are filtered automatically because you have to choose a user attribute of Active Directory, based on which members are automatically contacted when emails are sent to this group. So this is quite an easy way to minimize administrative overhead and costs in order to manage distribution lists.

Static Distribution Lists

Static distribution lists have existed in Exchange (also in what is formerly known as MS Mail) as long as mail systems have existed. They are used to sending information to a group of users as if it were only one user. As soon as the email reaches the server, it looks into the group memberships and sends the same message to all group members. If you want, you can allow every user to see (or not see – depending on the configuration) which users are included in the group itself.

To create a static distribution list called “StaticDL”, you can use the following Exchange commandlet:

New-DistributionGroup -Name “StaticDL” -OrganizationalUnit “domain.com/users” -SAMAccountName “StaticDL” -Type “Distribution”

To add a user called “JDoe” to the static distribution list, you can use the following Exchange commandlet:

Add-DistributionGroupMember -Identity “StaticDL” -Member [email protected]

To manage the membership of static distribution groups, you need to configure the following settings within Exchange:

Figure 1: Membership Approval Options of Static Distribution Lists

This new feature allows you to configure how users and distribution group managers can organize themselves group memberships on a self-service basis. This is quite important for the new Exchange Control Panel (ECP) for self-servicing group memberships.

The main disadvantage of using static distribution lists is that they need a manual task to join and disjoin users. If there is no process defined in the organization to make sure that only users who need to be members of this group are really members and that no orphaned users still reside in distribution lists, this feature is very powerful for everybody in the Exchange organization.

Dynamic Distribution Lists

In comparison to this, the configuration of dynamic distribution lists is a little bit easier as you can see below. Dynamic Distribution Lists was a new feature of Exchange Server 2003 and came into Exchange to provide an easy way to automatically create groups without having to add users to these groups manually.

To create a dynamic distribution list for all mail users of an OU called “MailUsers”, you can use the following Exchange commandlet:

New-DynamicDistributionGroup -IncludedRecipients MailboxUsers -Name “DynamicDL” -OrganizationalUnit MailUsers

Although you can create distribution groups with Exchange Management Console, too – it is more comfortable to use the Exchange Management Console for this task.

The owner of a distribution list can be configured as follows:

Figure 2: Defining Group Managers for Distribution Lists

As a group manager you can fully administer the group itself.

Joining a dynamic distribution group means that you need to know which attribute is being filtered for the distribution group and then change it. In general, each user can change his Active Directory attributes himself without having any administrative rights. This will then mean that there is the risk for group hijacking. What do I mean by this? In case of hijacking situation, users can get information they should not get just by being in a wrong dynamic distribution group.

Exchange Control Panel

With the new Exchange Control Panel (ECP) you can easily manage group memberships yourself. This new “Self-Service” feature can be configured directly from Outlook Web App. It allows each user to add an individual to a group or to remove him/her from one.

As a prerequisite, you need to configure each group membership as “Open” or “Owner Approval” (as seen in Figure 1) to make sure that users can join or disjoin these specific groups themselves.

If a user called “JDoe” wants to add him/herself to a group or leave a group he can do this as follows:

Figure 3: How to launch the Exchange Control Panel

Launching the Exchange Control Panel (ECP) is quite easy and can be done directly from Outlook Web App if you click on “Options” in the upper right corner of the window. Another way is to use this URL https://servername.domain.tld/ecp, which opens the same window.

Figure 4: Join or leave groups using Exchange Control Panel

Here you can choose the option “Groups” to join a group as a new member or to leave it the same way. With  just “one click” you are successful!

Conclusion

As you have seen in this article, with Exchange Server 2010 you will have great possibilities to deal with distribution groups, both static or dynamic ones. The most important thing is that you need to decide before starting with the distribution list enrollment whether to use static or dynamic distribution lists in each group you need. Converting from static to dynamic distribution lists and vice versa is impossible. This would mean you need to delete the group and recreate it again.

Distribution groups are a powerful way to provide users with easily spreadable information to users across the whole organization. And if you have a look at most of the distribution list designs in real world deployments, you will see that they generally fit into the organizational structure or describe the projects and/or teams within a company.

If your company moves to Exchange Server 2010, it is a big deal to design a distribution list plan that perfectly fits into your organization. For further questions please do not hesitate to contact me.