Exchange: Get a list of Distribution Groups

Get-ExchangeDistributionGroupBatch.ps1

#This exploits the fact that you can have up to 500 filter parameters to a get-distributiongroup query (but I do 450 here to be conservative)
#This is much faster than trying to do it via runspaces.
function Get-DistributionGroupBatch {
	param(
		[string[]]$Name,
		[int]$BatchSize = 450
	)

	for ($i, $i -lt $Name.Count; $i += $BatchSize) {
		$batch = $Name[$i..([Math]::Min($i + $BatchSize - 1, $Name.Count - 1))]
		$filter = ($batch | ForEach-Object { "Name -eq '$_'" }) -join ' -or '
		Get-DistributionGroup -Filter $filter
	}
}