Use a check for archiveDB for Get-OnPremExchangeMailboxStatistics

$ArchiveGB = Get-MailboxStatistics -identity ($Mailbox.Guid).ToString() -Archive -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | ForEach-Object {
    [Math]::Round([Double]($_.TotalItemSize -replace '^.*\(| .+$|,') / 1GB, 4)
}
# for example we are already doing this in EXO (remove foreach-object as seen also)
if ($Mailbox.ArchiveDatabase) {
    $ArchiveGB = Get-EXOMailboxStatistics -ExchangeGuid ($Mailbox.Guid).ToString() -Archive -Properties LastLogonTime -Verbose:$false | Select-Object @(
        @{
            Name       = 'ArchiveStat'
            Expression = { [Math]::Round([Double]($_.TotalItemSize -replace '^.*\(| .+$|,') / 1GB, 4) }
        }
    )
}

kevinblumenfeld / Posh365

Use a check for archiveDB for Get-OnPremExchangeMailboxStatistics #30