How Can I Export OWA Enabled Users with Their Mailbox Size to CSV?

It might help to debug your script. I feel like some people jump to asking for help before trying simple debugging techniques. Try stepping through your code line by line and see where it goes wrong – it can really help you understand the problem better.

One thing to keep in mind is that `Get-CASMailbox` doesn’t return 'UserPrincipalName' as a property, which is probably why your `$user` variable ends up being null. Instead, try using the `PrimarySMTPAddress` or `SamAccountName` attributes to get the user's identity.

First, try running `Get-CASMailbox -ResultSize Unlimited | Where-Object { $_.OWAEnabled -eq $true }` by itself to see if it's returning anything. If you're getting null, that might be your issue right there.

Honestly, I think we should encourage more self-debugging. It feels like the effort to troubleshoot should come first before seeking help. When someone poses a question without trying even simple fixes, it just sets a bad precedent. Let’s help them learn to tackle their own problems instead of handing them solutions.

Break your script down step by step: first, get all OWA-enabled mailboxes. Then, loop through each mailbox to validate what you’ve retrieved. Make sure to check if the mailbox object is valid before calling `Get-MailboxStatistics` on it. Construct your `PSCustomObject` only when you're sure everything is working. Here's a simple structure:

```powershell
$results = Get-CASMailbox -ResultSize Unlimited | Where-Object { $_.OWAEnabled -eq $true }
foreach ($SingleMailbox in $results) {
$stats = $SingleMailbox | Get-MailboxStatistics
[PSCustomObject]@{
Username = $SingleMailbox.PrimarySMTPAddress
MailboxSize = if ($stats) { $stats.TotalItemSize.ToString() } else { 'NA' }
}
}
```
Try running that and see if it helps!