Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2011-10-20

Dynamic distribution groups are mail-enabled Active Directory group objects that are created to expedite the mass sending of e-mail messages and other information within an Exchange organization.

Unlike regular distribution groups that contain a defined set of members, the membership list for dynamic distribution groups is calculated each time a message is sent to the group, based on the filters and conditions that you define. When an e-mail message is sent to a dynamic distribution group, it's delivered to all recipients in the organization that match the criteria defined for that group.

Caution:
  • A dynamic distribution group includes any recipient in Active Directory with attributes that match its filter. If a recipient's properties are modified to match the filter, the recipient could inadvertently become a group member and start receiving messages that are sent to the group. Well-defined, consistent account provisioning processes will reduce the chances of this issue occurring.

  • Take caution when creating or modifying dynamic distribution groups within search scopes, such as organizational unit (OU).

  • Avoid creating multiple levels of dynamic distribution group membership (also known as nested groups) as this may cause increased LDAP requests and initiate slow LDAP responses.

Looking for other management tasks related to dynamic distribution groups? Check out Managing Distribution Groups.

What Do You Want to Do?

Use the EMC to configure dynamic distribution group properties

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Dynamic distribution groups" entry in the Mailbox Permissions topic.

  1. In the console tree, navigate to Recipient Configuration > Distribution Group.

  2. In the result pane, click the dynamic distribution group that you want to configure.

  3. In the action pane, click Properties.

  4. Use the General tab to view or modify the display name, alias, and custom attributes for the dynamic distribution group.

    • Display name   Use this unlabeled text box at the top of the page to view or change the display name for the group.

    • Organizational unit   This read-only field displays the organizational unit (OU) that contains the group.

    • Modified   This read-only field displays the last date and time a configuration change was made.

      Note:
      Configuration changes made through any other method, such as the Exchange Management Shell or Active Directory Service Interfaces (ADSI) Edit, will also update this field.
    • Alias   Use this box to view or change the alias of the group. The alias cannot exceed 64 characters and must be unique in the forest.

    • Custom Attributes Click this button to open the Custom Attributes dialog box. You can specify up to 15 custom attributes for the recipient. To specify the custom attribute values, use the corresponding boxes, and then click OK. To learn more, see Understanding Custom Attributes.

  5. Use the Group Information tab to change the Active Directory information for the dynamic distribution group.

    • Name   Use this box to view or change the name of the group. The name can't exceed 64 characters.

    • Managed By   The recipient that's designated as the manager for this dynamic distribution group will be visible when users view the properties of this group in Outlook or Outlook Web App. If the delivery reports option on the Advanced tab is set to Send delivery reports to group manager, the manager will also receive delivery reports for the group.

      Click Add to open the Select Mailbox or Mail-enabled User dialog box. Use this dialog box to select the recipient you want to add as a manager of the group, and then click OK.

      Click Remove icon to remove the selected manager from the dynamic distribution group.

    • Notes   Use this box to view or modify administrative notes about the group. These notes are also visible in Outlook. When a user views the properties of the group in Outlook, the notes will be displayed on the General tab.

  6. Use the Filter tab to modify the recipient filter for the group:

    • Select the recipient container where you want to apply this filter   This box is populated with the OU that you selected when you created the dynamic distribution group. To specify a different OU, click Browse to open the Select Organizational Unit dialog box. A dynamic distribution group contains all recipients that are in the specified OU and any other OUs under it.

    • Select the recipient types you want to include. You can select All recipient types or The following specific types. If you select The following specific types, you can select one or more of the following recipient types:

      Users with Exchange mailboxes   Select this check box if you want to include users that have mailboxes. Users that have Exchange mailboxes are those that have a user domain account and a mailbox in the Exchange organization.

      Users with external e-mail addresses   Select this check box if you want to include users that have external e-mail addresses. Users that have external e-mail accounts have user domain accounts in Active Directory, but use e-mail accounts that are external to the organization. This enables them to be included in the global address list (GAL) and added to distribution lists.

      Resource mailboxes   Select this check box if you want to include Exchange resource mailboxes. Resource mailboxes allow you to administer company resources through a mailbox, such as a conference room or company vehicle.

      Contacts with external e-mail addresses   Select this check box if you want to include contacts that have external e-mail addresses. Contacts that have external e-mail accounts do not have user domain accounts in Active Directory, but the external e-mail address is available in the GAL.

      Mail-enabled groups   Select this check box if you want to include security groups or distribution groups that have been mail-enabled. Mail-enabled groups are similar to distribution groups. E-mail messages that are sent to a mail-enabled group account will be delivered to several recipients.

  7. Use the Conditions tab to define any optional conditions to further restrict the recipients that are included in this dynamic distribution group.

    • Step 1: Select conditions   Use this section to select one or more conditions. If you don't want to set any conditions for the list, don't select any of the check boxes.

    • Step 2: Edit the conditions by selecting an underlined value   If you select any conditions in Step 1, each condition you select will append to the definition. For example, if you selected the Recipient is in a State or Province check box, you'll see the in the specified State or Province(s) condition in Step 2.

      For each condition, click the underlined term to create your condition. By default, the underlined term for new conditions will read specified. After you edit the condition, the underlined term will change to the value that you specified.

      Important:
      The values that you enter in these dialog boxes must exactly match those that appear in the recipient's properties. For example, if you enter Washington in the Specify State or Province dialog box, but the Address and Phone tab in the recipient's properties lists the state as WA, the condition will not be met.
    • Preview   Click this button to view the recipients that will be included, based on the conditions that you specified.

      Note:
      If you want to specify conditions other than the ones available on this tab, you must use the Exchange Management Shell to create a custom query for the dynamic distribution group. Keep in mind that the filter and condition settings for dynamic distribution groups that have custom recipient filters can be managed only by using the Shell. For more information about recipient filters, see Creating Filters in Recipient Commands.
  8. Use the E-Mail Addresses tab to configure the e-mail addresses for the recipient. You can modify the existing addresses or create additional ones. Each recipient must have at least one primary STMP address that is internal to your Exchange organization and one external address.

    • Add   Click Add to add a new e-mail address for this recipient. Use the drop-down box to select from the following address types:

      SMTP Address   This is the default address type. Click this button and use the corresponding dialog box to add an SMTP address.

      EUM Address   This address type is available only for user mailboxes. It's not available for mail users, mail contacts, distribution groups, or mail-enabled public folders. An EUM (Exchange Unified Messaging) address is used by Unified Messaging servers to locate UM-enabled users within an Exchange 2010 organization. EUM addresses contain the extension number and the UM dial plan for the UM-enabled user. Click this button and use the corresponding dialog box to add an EUM address.

      Custom Address   Click this button and use the corresponding dialog box to add a custom address (for example, fax or X.400).

      Note:
      With the exception of X.400 addresses, Exchange doesn't validate custom addresses for proper formatting. You must make sure that the custom address you specify complies with the format requirements for that address type.
    • Edit   Click this button to modify the selected e-mail address.

    • Remove icon   Click this button to remove the selected e-mail address.

    • Set as Reply   Click this button to set your selected address as the "reply to" address. A recipient can have multiple e-mail addresses for a specific address type. This allows the recipient to receive messages that are addressed to any one of these e-mail addresses. However, a single address must be used for any messages that are sent by the recipient. If a recipient has multiple e-mail addresses, the primary address is used for any messages sent by the recipient.

      This button is available only when an address other than the primary address is selected. Primary addresses for each address type are displayed in bold type.

      If an e-mail address policy in your Exchange organization applies to this mailbox, the Set as Reply setting will be controlled by that policy. To change the primary address for a specific address type, you must clear the Automatically update e-mail addresses based on e-mail address policy check box.

    • Set as External   This button is available only for mail users and mail contacts. It's not available for user mailboxes, distribution groups, or mail-enabled public folders. Click Set as External to designate the selected e-mail address as the external e-mail address for the recipient.

      Note:
      This button is enabled when an address other than the external e-mail address is selected.
    • Automatically update e-mail addresses based on e-mail address policy   Select this check box to have the recipient's e-mail addresses automatically updated based on changes made to e-mail address policies in your organization. This box is selected by default.

  9. Use the Advanced tab to view or change the advanced group settings, such as the expansion server and delivery report options.

    • Simple display name   Use this box to view or modify the simple display name for the group. The Display name field (located on the General tab) can contain Unicode characters. However, third-party applications and older clients may not support Unicode characters. If the system that is displaying the recipient properties doesn't support Unicode characters, you can use the simple display name. For more information about Unicode characters, see Unicode. The simple display name field accepts only ASCII characters.

    • Set expansion server   For each message that is sent to the dynamic distribution group, Exchange must access the full membership list to route the message to all recipients. This process is known as distribution group expansion. Use this box and corresponding Browse button to select a Hub Transport server in your Exchange organization that will be responsible for expanding the membership list for this group

      Expansion of very large dynamic distribution groups is a resource intensive process. If it occurs on a production server, it may impact mail flow. To avoid any production impact, you may want to specify expansion servers for very large groups.

    • Hide from Exchange address lists   Select this check box to prevent the recipient from appearing in the global address list (GAL) and other address lists that are defined in your Exchange organization.

      After you select this check box, users in your Exchange organization can still send messages to the recipient by using the e-mail address.

    • Send out-of-office message to originator   Select this check box to allow Out of Office messages from group members to be sent to the message sender. If this check box is selected, users who send messages to the group will receive Out of Office replies from any member that has an Out of Office rule turned on.

      Clear this check box to prevent Out of Office replies from group members to be sent to the message sender.

    • Send delivery reports to group manager   Click this button to send non-delivery reports (NDRs) to only the group manager.

    • Send delivery reports to message originator   Click this button to send NDRs to the message sender.

    • Do not send delivery reports   Click this button to prevent the sending of NDRs.

  10. Use the Mail Flow Settings tab to configure message size or message delivery restrictions for the dynamic distribution group. To view or change a mail flow setting, select the setting from the list, and then click Properties.

    • Message Size Restrictions   Select this setting and then click Properties to open the Message Size Restrictions dialog box. Use this dialog box to configure the maximum message size in kilobytes (KB) that users are allowed to send to this group.

      If a message larger than the specified size is sent to the group, the message will be returned to the sender with a descriptive error message.

      In the Message Size Restrictions dialog box, select the Maximum message size (in KB) check box to set the maximum size for messages that can be received by this group. Use the corresponding box to specify the maximum message size allowed (in KB). The message size must be between 0 and 2,097,151 KB.

      Clear the Maximum message size (in KB) check box to remove the size restrictions for receiving messages.

    • Message Delivery Restrictions   Select this setting and then click Properties to open the Message Delivery Restrictions dialog box. Use this dialog box to configure the following settings:

      All senders   Click this button to allow the group to accept messages from all senders. This includes senders in both your Exchange organization and external senders. This button is selected by default. This option includes external users only if you clear the Require that all senders are authenticated check box. If you select this check box, messages from external users will be rejected.

      Only senders in the following list   Click this button to specify that the group can accept messages only from a specified set of senders in your Exchange organization. Click Add to open the Select Recipient dialog box. This dialog box displays a list of all recipients in the Active Directory forest. Select the recipients you want, and then click OK. You can also search for a specific recipient by typing its name in the Search box and then clicking Find Now.

      Require that all senders are authenticated   Select this check box to prevent anonymous users from sending messages to the group. By default, this check box is selected for dynamic distribution groups. This prevents external senders from sending messages to dynamic distribution groups.

      No Senders   Click this button to specify that the group will not reject messages from any senders in the Exchange organization. This button is selected by default.

      Senders in the following list   Click this button to specify that the group will reject messages from a specified set of senders in your Exchange organization. Click Add to open the Select Recipient dialog box. This dialog box displays a list of all recipients in the Active Directory forest. Select the recipients you want, and then click OK. You can also search for a specific recipient by typing its name in the Search box and then clicking Find Now.

Use the Shell to configure dynamic distribution group properties

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Dynamic distribution groups" entry in the Mailbox Permissions topic.

This example changes the MaxSendSize property to 20MB and sets the ModerationEnabled property to $True:

Copy Code
Set-DynamicDistributionGroup "Seattle Employees" -MaxSendSize 20MB -ModerationEnabled $True

This example adds a second SMTP e-mail address and changes the group manager to John.

Copy Code
Set-DynamicDistributionGroup -Identity "Seattle Employees" -ManagedBy 'mail.contoso.com/Users/John' -EmailAddresses 'smtp:Seattle.Employees@mail.contoso.com' 'smtp:SeattleEmployees@mail.contoso.com' 

For detailed syntax and parameter information, see Set-DynamicDistributionGroup

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