Nested DLs Nightmare. Please HELP

Question

Can someone help me add to this function to where I can feed 300+ DLs into it to get the number of members nested and un-nested in each DL. It works when hardcoded in the $group variable. When it runs it displays all the members and the $members.count gives me the number of members in the DL. I have to convert 300+ mail enabled security groups to DL. Before working with them I want to work with the ones with the least number of members first.

$group = "DL-Name"
$members = New-Object System.Collections.ArrayList

Create the Function

function getMembership($group) {  
    $searchGroup = Get-DistributionGroupMember $group -ResultSize Unlimited  
    foreach ($member in $searchGroup) {  
        if ($member.RecipientTypeDetails-match "Group" -and $member.DisplayName -ne "") {  
            getMembership($member.DisplayName)  
            }             
        else {  
            if ($member.DisplayName -ne "") {  
                if (! $members.Contains($member.DisplayName) ) {  
                    $members.Add($member.DisplayName) >$null  
                    }  
                }  
            }  
        }  
    }  

Run the function

getMembership($group)  

Output results to screen

##$members.GetEnumerator() | sort-object > .\all_members_mailing_list.csv   
$members | Select @{N="UserName";E={$_}}  
$members.count  

Answer 1

Not sure I understand the question here? The code should work for both "regular" DGs and mail-enabled security ones (fixed membership).
Here's a reference script I did a while back that should output membership of nested groups: https://github.com/michevnew/PowerShell/blob/master/DG_members_recursive.ps1
And the accompanying article with more details: https://practical365.com/how-to-inventory-membership-of-exchange-groups-recursively/

Answer 2

@timednfl

Why not add a loop to your script directly, such as:

function getMembership($group) {  
    $searchGroup = Get-DistributionGroupMember $group -ResultSize Unlimited  
    foreach ($member in $searchGroup) {  
        if ($member.RecipientTypeDetails-match "Group" -and $member.DisplayName -ne "") {  
            getMembership($member.DisplayName)  
            }             
        else {  
            if ($member.DisplayName -ne "") {  
                if (! $members.Contains($member.DisplayName) ) {  
                    $members.Add($member.DisplayName) >$null  
                    }  
                }  
            }  
        }  
    }  
  
$allGroups = Get-DistributionGroup -ResultSize Unlimited  
foreach ($allgroup in $allGroups) {  
    $members = New-Object System.Collections.ArrayList  
    Write-Host ("`nInformation about "+$allgroup)  
    getMembership($allgroup )  
    $members | Select @{N="UserName";E={$_}}  
    Write-Host ("Member Count "+$members.count)  
}  

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