ADManager Plus allows you to create Shared Mailboxes in both the on-premise Exchange Server as well as the on-demand Office 365 environments, either simultaneously or individually, from a single web-based console.
To create a new Shared Mailbox in Exchange Server and Office 365,
Click the AD Mgmt tab.
Select Mailbox Management from the options on the left hand side.
Click the create single shared mailbox link.
In the create single shared mailbox page, select the domain in which you wish to create a new shared mailbox.
Select the mailbox creation template that you wish to use to create the shared mailbox. If you do not specify any template, the default template specified by the administrator will be used.
Use the check boxes to choose whether you want to create the shared mailbox in Active Directory, Office 365 or both.
Click the General tab
Enter the appropriate values for all the fields. Display Name, E-mail and Container are mandatory attributes for creating a shared mailbox. All mandatory attributes will be highlighted in red.
Click the Contact tab and enter relevant values for all the telephone, organization and address fields.
Select the Exchange Tab and enter relevant values for all the fields. You must specify values for the Mailbox server, mailbox store and mail alias attributes which are mandatory for creating a shared mailbox.
In the Delegation tab, select the desired users for the send on behalf, send as and full access rights for this shared mailbox
In the Custom attributes tab, select the custom attributes ( configured in the schema) that you wish to add in ADManager Plus. To add a custom attribute permanently in the tool, click the configure custom attribute link; use the add additional attribute link to add a custom attribute for only a specific operation.
In the Office 365 tab, select the appropriate option from the ones listed to specify whether a shared mailbox has to be created in Office 365 as well, and also whether the DirSync option has to be enabled or disabled during mailbox creation.
In this tab you can assign specific permissions to the Office 365 users such as to select the desired users and grant 'send on behalf', 'send as', and 'full access' rights in this shared mailbox.
Click the Create button to create the new shared mailbox.