OA supports multiple mailbox stores per Exchange Backend server. The article describes how to configure OA to provision customers' mailboxes on different Exchange mailbox stores using provisioning attributes.


  1. Create and register new mailbox store in OA using the article #1178 How to create additional Mailbox Stores for Hosted Exchange.

  2. Create provisioning attributes, e.g. exchange_2 and exchange_store_2.

    Note: we will use exchange_2 as a provisioning attribute and it will be assigned to Exchange hosts, while exchange_store_2 is a mailbox store attribute and it will be used within Service Templates and assigned to Exchange mailbox stores, not hosts.

  3. Create new resource type based on the Hosted Exchange resource class and assign the exchange_2 provisioning attribute to it.

  4. Create new Service Template for Exchange hosting, include resource type created on the previous step into it and define the value of the Mailbox storage attributes (comma-separated values) template parameter as exchange_store_2.

  5. Assign the exchange_store_2 attribute to the new Exchange mailstore in OA Provider CP at Service Director > Hosted Exchange Manager > Mailbox Stores > select store > Attributes tab.

  6. Assign the exchange_2 provisioning attribute to the Exchange server where the new mailbox store is created.

    Note: Exchange host with ExchangeSMTP service should have the same provisioning attribute assigned as well.

  7. Mark the new mailstore as Ready to provide in OA Provider CP at Service Director > Hosted Exchange Manager > Mailbox Stores > select store > General tab.

Additional information

OA is looking for the target Exchange mailbox store for provisioning this way:

  1. OA detects the provisioning attribute of Resource Type Hosted Exchange from Service Template (exchange_2 in the example above).

  2. OA selects the Exchange BackEnd and FrontEnd servers with the same provisioning attribute (exchange_2).

  3. Detects the mailstore attribute from the Mailbox storage attributes activation parameter of Service Template parameter (exchange_store_2 in the example above).

  4. Selects the specific Exchange Mailbox Stores by mailstore attribute and select the one which has maximal not allocated size.

  5. Provisions new mailbox on the selected Mailbox Store.

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