Rackspace Directory Sync Administration Guide

  • Last updated on: 2019-01-23
  • Authored by: Kevin Richey

This article provides information for administrators using Rackspace Directory Sync. It includes information about how Directory Sync works with Active Directory® and how to use local domains to synchronize to Rackspace Hosted Email.

Using Directory Sync for your organization includes these benefits:

  • Same sign-on: Users have one password for their local network access and their email accounts for a same sign-on experience.
  • Ease of management: Administrators can manage mail-enabled objects directly from a familiar Microsoft® Active Directory interface. Choose which user objects to synchronize. Synchronize a single user in your Active Directory, or synchronize all of them at the same time.
  • Save time: Directory Sync can save considerable effort and time when onboarding new employees and managing password policies in large numbers.
  • Business automation: Rackspace Directory Sync is built to use the Rackspace Email public REST APIs to facilitate automation.
  • Secure: All data exchanged is encrypted by using Secure Sockets Layer (SSL), and synchronization is one-way only.
  • Cost effective: Rackspace Directory Sync is available at no additional cost.

Supported objects and platforms

Rackspace Directory Sync supports the synchronization of the following Active Directory objects:

  • Active Directory user mailboxes
  • Active Directory user passwords for same sign-on
  • Active Directory contacts (Hosted Exchange)
  • Distribution groups (Hosted Exchange)

Directory Sync supports the following Rackspace Email platforms:

  • Hosted Exchange 2010
  • Hosted Exchange 2013
  • Hosted Exchange 2016
  • Hosted Exchange Hybrid
  • Rackspace Email

Directory Sync supports the following Active Directory platforms:

  • Windows® 2012 and 2012 R2
  • Windows Server® 2008 and 2008 R2

Directory Sync limitations

  • Directory Sync does not synchronize with Hosted Exchange 2007.
  • Existing mail data does not migrate with Directory Sync to our hosted environment. We offer several methods that you can use to migrate your own data, as described in the article Email migration services.
  • Synchronizes user passwords at the moment a password is changed. Passwords cannot be synchronized retroactively because they are unreadable from Active Directory. Users must change their passwords for Directory Sync to synchronize the change with their mailbox.
  • Directory Syns is not Lightweight Directory Access Protocol (LDAP) compatible.
  • Windows Server 2003 and the Active Directory functional level of 2003 are not supported.

Installation and configuration

See Rackspace Directory Sync: Install and configure to get started.

Note: You must restart the domain controller during installation in order for the password synchronization to work.

How Directory Sync works

Directory Sync automatically synchronizes changes from your local directory to your email accounts every five minutes. You can also click Sync Now to synchronize immediately.

Directory Sync synchronizes one-way only. It does not synchronize information from Hosted Exchange or Rackspace Email back to your Active Directory. If you change any information, such as passwords, by using Outlook® Web App or Control Panel, your mailboxes are not synchronized with Active Directory.

Domain names

Directory Sync synchronizes one local Active Directory domain with multiple email domains.

The domain names can be the same or different. You specify the local Active Directory domain at set up.

Security groups

Directory Sync uses Active Directory security groups to manage which objects are synchronized with your email service. If you use Hosted Exchange, create a new security group for the users that synchronize with Exchange mailboxes. If you use Rackspace Email, create a new security group for the users that synchronize with Rackspace Email mailboxes. If you use both Hosted Exchange and Rackspace Email, you create two security groups. Directory Sync creates and manages mailboxes for all user objects that you add to the security groups.

User mailboxes

Directory Sync associates Active Directory user objects with email accounts by using their mail attribute. The mail attribute is the email address property associated with the user.

Password synchronization

Password synchronization occurs after the user object has synchronized to the mailbox. Password changes occur on their own synchronization interval and with a higher priority than other synchronization sessions.

When you install Directory Sync, it cannot automatically synchronize existing passwords because they are unreadable from Active Directory. Users continue to use their old email passwords. When users manually change their password, Directory Sync synchronizes it with their mailbox. Be sure to assign user objects to email security groups before you change passwords. Otherwise, Directory Sync does not set the new passwords.

When you create new mailboxes, those users must change their passwords before they can access their email.

If you manage your Active Directory with multiple domain controllers, you must install the Directory Sync Password Handler on all secondary domain controllers. This handler is used to synchronize password changes on secondary domain controllers to the primary domain controller and then synchronize those changes to Rackspace Hosted Mail.

Distribution list membership synchronization

Synchronize users within distribution lists or security groups from Active Directory to distribution list membership within the Control Panel. Directory Sync uses the group’s email address property to synchronize with the Hosted Exchange distribution list.

Exchange contacts

Synchronize contact objects within Active Directory to your Exchange contacts within the Hosted Exchange environment. Within Active Directory, you can set up the external email address to which the contact forwards. Directory Sync uses the contact object’s mail attribute to set this.

Alternate email addresses (optional synchronization)

The proxyAddresses attribute is used to create alternate email addresses (aliases) for the Hosted Exchange environment. If you set the proxyAddresses attribute to include SMTP: userA@example.net, then Directory Sync adds the address userA@example.net to the environment as an alias to that email address.

  • Any address that begins with smtp: in the proxyAddresses attribute creates an alternate email address associated with the user’s mailbox.
  • These addresses cannot include a domain alias in the address but can include either the primary domain or accepted domains.
  • You can create alternate email addresses associated with domain aliases by using the primary domain. For example, smtp:userB@example.com creates the alternate address userB@example.net.
  • Accepted domains are created with the full email address (including the domain). For example, smtp:userA@example.org creates the alternate address userA@example.org.

How to enable synchronization of proxy addresses:

  1. The setting is located in the appSettings.config file in the \Directory Sync Service\web directory.
  2. Go to the following configuration value:

    <add key="SyncProxyAddresses" value="False" />

  3. Change the setting to True to enable syncing of the proxy addresses. Future upgrade installations do not revert this setting.

Additional notes

  • The Attribute Editor is visible in the Active Directory Users and Computer (ADUC) console with the Advanced Features enabled in the View tab.
  • You must configure domain aliases and accepted domains with the help of Cloud Office Support before configuring alternate addresses to ensure that they are synchronized correctly.
  • During the initial set up, ensure the proxyAddresses attribute does not contain any domain aliases to avoid errors.
  • Alternate addresses are available to Exchange mailboxes only. They do not work with distribution lists or contacts.


This section describes some security considerations.

User password requirements

Directory Sync does not set an email password that does not meet minimal password requirements. We recommend that you change your domain password rules to meet or exceed these requirements.

Rackspace Email and Hosted Exchange password requirements

Note the following email requirements:

  • At least eight characters long
  • At least 3 of the following:
    • At least one lowercase character
    • At least one uppercase character
    • At least one number
    • At least one non-alphanumeric (!, $, #, %, space, and so on)

Network ports

You do not have to open any inbound ports from the Internet to your domain controllers.

Enable the following ports on the Directory Sync server:

  • 443 - Outbound HTTPS connections from Directory Sync service to Rackspace API
  • 8732 - Open for connections from other domain controllers to the Directory Sync server. Not used for any connections outside your network. The domain controller password hooks use this port.
  • 8080 - This port is only used locally on the Directory Sync service machine for the web browser. You may block this port for any external connections.

Network encryption

HTTPS secures communications between Directory Sync and Rackspace. Microsoft® WCF Transport Security, which uses Windows Authentication and encryption, secures communications between the Active Directory password hook and Directory Sync.

Synchronized user attributes

Directory Sync synchronizes the following user attributes with Hosted Exchange and Rackspace Email mailboxes. Some attributes differ between Rackspace Email and Exchange mailboxes.

List Format: Email Attribute: Active Directory Services Interface (ADSI) property (limitations)

  • Email Address: mail
  • Password: password
  • Display Name: displayName
  • Last Name: sn
  • First Name: givenName
  • Generation Qualifier: generationQualifier (Rackspace Email only)
  • Initials: initials (Rackspace Email only)
  • Organization Unit: o (Rackspace Email only)
  • Business Number: telephoneNumber
  • Pager Number: pager
  • Home Number: homePhone
  • Mobile Number: mobile
  • FAX Number: facsimileTelephoneNumber
  • Home FAX Number: otherFacsimileTelephoneNumber (Rackspace Email only)
  • Street: streetAddress
  • City: l
  • State: st
  • Postal Code: postalCode
  • Country: co
  • Title: title
  • User ID: employeeID (Rackspace Email only)
  • Employee Type: employeeType (Rackspace Email only)
  • User Account Control: userAccountControl
  • Company: company (Exchange only)
  • Department: department (Exchange only)
  • Proxy Addresses: proxyAddresses (Exchange only)
  • Office: physicalDeliveryOfficeName (Exchange only)

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