Exchange 2010 suppress Get-MailboxStatistics warnings

Question

How do I suppress warnings from Exchange 2010's PowerShell Get-MailboxStatistics cmdlet?

I've tried both of these options:

Get-MailboxStatistics -WarningAction SilentlyContinue
Get-MailboxStatistics -ErrorAction SilentlyContinue

However I still get this warning output to the console about users that's haven't logged onto their mailboxes:

WARNING: The user hasn't logged on to mailbox ...[snipped]..., so there is no data to return. After the user logs on, this warning will no longer appear.

Answer 1

I also tried $WarningActionPreference = "SilentlyContinue" --This will set all warning messages to silent. Looks like something is broken. Looks like there is a bug.

https://connect.microsoft.com/PowerShell/feedback/details/541500/warning-verbose-and-debug-streams-do-not-respect-action-preferences-the-way-they-should

Answer 2

I've been playing with this one, trying to recreate the issue (I'm on Exhcange 2007, though, so this may make a difference. I'm also pretty new to powershell). Starting with a new mailbox, "Testy McTest":

>get-variable |where { $_.Name -match "Preference" }

Name                           Value
----                           -----
ConfirmPreference              High
DebugPreference                SilentlyContinue
ErrorActionPreference          Continue
ProgressPreference             Continue
VerbosePreference              SilentlyContinue
WarningPreference              Continue
WhatIfPreference               False

I can run the following:

>Get-MailboxStatistics "Testy McTest"
WARNING: There is no data to return for the specified mailbox 'Testy McTest', because it has not been logged on to.
>Get-MailboxStatistics -WarningAction SilentlyContinue "Testy McTest"   (No Output)
>Set-Variable WarningPreference SilentlyContinue
>Get-MailboxStatistics "Testy McTest"   (No output)
>

This seems to work as normal. It might be worth mentioning that the variables for Error and Warning actions are actually ErrorActionPreference and WarningPreference. Not sure why they differ like that.

As a workaround for the specific command in the question, you could qualify the output, with something like:

>Get-MailboxStatistics |where { $_.LastLogonTime }

Which seems to list only those mailboxes that have a logon time.