def mailbox!(mbox)
      nbuild[NS_EWS_TYPES].Mailbox {
        name!(mbox[:name]) if mbox[:name]
        email_address!(mbox[:email_address]) if mbox[:email_address]
        address!(mbox[:address]) if mbox[:address] # for Availability query
        routing_type!(mbox[:routing_type]) if mbox[:routing_type]
        mailbox_type!(mbox[:mailbox_type]) if mbox[:mailbox_type]
        item_id!(mbox[:item_id]) if mbox[:item_id]
      }
    end
def mailbox!(mbox)
      nbuild[NS_EWS_TYPES].Mailbox {
        name!(mbox[:name]) if mbox[:name]
        email_address!(mbox[:email_address]) if mbox[:email_address]
        address!(mbox[:address]) if mbox[:address] # for Availability query
        routing_type!(mbox[:routing_type]) if mbox[:routing_type]
        mailbox_type!(mbox[:mailbox_type]) if mbox[:mailbox_type]
        item_id!(mbox[:item_id]) if mbox[:item_id]
      }
    end
Build the Mailbox element.
 This element is commonly used for delegation. Typically passing an
   email_address is sufficient
 @see http://msdn.microsoft.com/en-us/library/aa565036.aspx
 @param [Hash] mailbox A well-formated hash