Returning an array from COM+ component

Hi I return an array from a COM+ component however when I try to access the data from the .cs code, I get the following error:
System.NullReferenceException: Object reference not set to an instance of an object. at SSEF._Default.EnableForwarding(String domain, String domainController, String username)


for the line
EmailAddress = mailbox[0]


This is the component calling code:
private void EnableForwarding(string domain, string domainController, string username)
{
Response.Write(string.Format("<b>Web Application Context:</b> {0}<br>", WindowsIdentity.GetCurrent().Name));

// Create the COM+ component
PowerShellComponent.ManagementCommands objManage = new PowerShellComponent.ManagementCommands();

String[] mailbox = new string[2];
...