Creating Exchange Server mailbox-enabled and mail-enabled objects in Active Directory

This article describes how Microsoft Exchange Server mailbox-enabled and mail-enabled objects are created in Active Directory.

A mail-enabled object is a Windows 2000 Active Directory object that has at least one e-mail address defined. An example of a mail-enabled object is an Exchange Server contact that has an e-mail address defined.

A mailbox-enabled object is a Windows 2000 Active Directory object that has one or more Exchange Server mailboxes associated with it. In Exchange 2000, only a user object can have a mailbox. To be mailbox-enabled, an object has to be a Windows 2000 Active Directory security principal (that is, the object must be able to log on).

A user is a Windows 2000 Active Directory security principal which optionally may have an Exchange Server e-mail addresses or an Exchange Server mailbox or both. A user can be either mail-enabled or mailbox-enabled.

When you use the Active Directory Management Agent in Microsoft Metadirectory Services (MMS), both mailbox-enabled and mail-enabled objects can be created in Active Directory. The following information includes the specific attributes that are required to create each type of object in Active Directory. This information should be taken into consideration when you configure attribute flow and construction templates in MMS.

Creating Mailboxes

Mandatory attributes

• mailNickname: This attribute is the alias to the mailbox.
• displayName: This attribute is the text that is the readable name that represents you for mail delivery, and in the address book.
• One of the three attributes in the following list:
  • homeMTA: This attribute is a distinguished name to the Message Transfer Agent (MTA) object where your mailbox resides.
  • homeMDB: This attribute is a distinguished name to the private Messaging Database (MDB) where your mailbox resides.
  • msExchHomeServerName: This attribute is the legacy distinguished name to the server where you have a mailbox (that is, /o=org/ou=site/cn=configuration/cn=servers/cn=server).

Optional attributes

• homeMDB: This attribute is a distinguished name to the MTA object where your mailbox resides. If this attribute is not specified, it is derived from one of the server attributes previously defined. If your Exchange Server computer contains more than one store, Exchange Server randomly chooses one.
• homeMTA: This attribute is a distinguished name to the private MDB where your mailbox resides. If this attribute is not specified, it is derived from one of the server attributes previously defined.
• msExchHomeServerName: This attribute is the legacy distinguished name of the server where you have a mailbox (that is, /o=org/ou=site/cn=configuration/cn=servers/cn=server). If this attribute is not specified, it is derived from one of the server attributes previously defined.
  
  Note At least one of the three attributes that are listed above must be specified when you create a mailbox-enabled object. If only one attribute is specified, the value for the others is taken from the one specified attribute.
• E-mail address attributes: If you specify one or all of these attributes, Exchange Server does not generate the defaults for you. If you do not specify these attributes, Exchange Server generates all three attributes for you, based on the rules set up for your Exchange Server computer:
  • proxyAddresses: A multi-valued attribute that contains all the e-mail addresses for which you can receive mail. The format of this attribute is PREFIX:proxy, where PREFIX is either SMTP, X400, GWISE, or NOTES, for example, SMTP:gyip@microsoft.com.
  • mail: This attribute contains the primary SMTP address for this mailbox. This attribute does not have an address prefix, and it contains only the SMTP address, for example, gyip@microsoft.com.
  • textEncodedOrAddress: This attribute contains the primary x400 address for this mailbox. This attribute does not have an address prefix, and it contains only the x400 address, for example, c=us,a= ;p=First Organizati;o=Exchange;s=yip;g=geeman;.
• legacyExchangeDn: This attribute is a unique legacy distinguished name which identifies your mailbox. This attribute is mainly used for backwards compatibility purposes for the Mail Application Programming Interface (MAPI) clients, for example, /o=org/ou=site/cn=recipients/cn=gyip. If this attribute is not specified, a random distinguished name is generated for you. This value contains the location of the physical object in the Exchange Server 5.5 directory service; therefore, if you specify a value here for the object in Active Directory, the Active Directory Connector (ADC) may change the value, depending on where the physical object is created by means of the ADC.

Note Do not set the targetAddress attribute when you create a mailbox-enabled user. This attribute should only accompany mail-enabled objects.

Creating Mail-Enabled Objects

Mandatory Attributes:

• mailNickname: This attribute is the alias to the mailbox.
• displayName: This attribute is the text that is the readable name that represents you for mail delivery, and also in the address book.
• targetAddress: This attribute is the e-mail address to which you want to redirect the mail. This attribute is formatted like the proxyAddresses attribute, where there is a prefix that defines the address type, for example, "SMTP:gyip@microsoft.com".

Optional Attributes

• E-mail address attributes: If you specify one or all of these attributes, Exchange Server does not generate the defaults for you. If these attributes are not specified, Exchange Server generates all three attributes for you, based on the rules set up for your Exchange Server computer:
  • proxyAddresses: A multi-valued attribute that contains all the e-mail addresses for which you can receive mail. The format of this attribute is PREFIX:proxy, where PREFIX is either SMTP, X400, GWISE, or NOTES, for example, SMTP:gyip@microsoft.com.
  • mail: This attribute contains the primary SMTP address for this mailbox. This attribute does not have an address prefix and it only contains the SMTP address, for example, gyip@microsoft.com.
  • textEncodedOrAddress: This attribute contains the primary x400 address for this mailbox. This attribute does not have an address prefix, and it only contains the x400 address, for example, c=us,a= ;p=First Organizati;o=Exchange;s=yip;g=geeman;.
• legacyExchangeDn: This attribute is a unique legacy distinguished name which identifies your mailbox. This attribute is mainly used for backwards compatibility purposes for MAPI clients, for example, /o=org/ou=site/cn=recipients/cn=gyip. If this attribute is not specified, Exchange Server generates a random distinguished name for you. This value contains the location of the physical object in the Exchange Server 5.5 directory service; therefore, if you specify a value here for the object in Active Directory, the ADC may change the value, depending on where the physical object is created by means of the ADC.

For more information about user and contact objects in Active Directory, click the following article number to view the article in the Microsoft Knowledge Base:

Known issues

The following items should be considered when you mail-enable existing objects:

• If you use the LDIFDE tool to update (import) attributes to make an existing object mail-enabled, you must make sure that the legacyExchangeDn attribute is valid or blank. This is because either a valid or invalid existing value, such as ADCDisabledMail or ADCMailDisabledbyADC, will not be changed by the Recipient Update Service.
• The "Mail Enable Recipient" Recipient Policy does not include Dynamic Distribution Lists in its filter. Therefore, the Recipient Update Service does not stamp the legacyExchangeDn attribute on Dynamic Distribution Lists. This requires that you set the legacyExchangeDn attribute on Dynamic Distribution List objects either manually or by using an LDIFDE import.