How to export Distribution List & its nested Distribution Lists' members to CSV file

Use PowerShell, or if you don't know how to write such a script, look up examples online - there are plenty such scripts. Here is one of mine: https://www.michev.info/blog/post/4394/report-on-recursive-group-membership-via-exchange-powershell

Hi, @raj a

As Vasil Michev said, using Power Shell is the fastest way to operate with large distribution lists.

Unfortunately, the current Exchange tag is not focused on providing scripting. I'm going to add Power Shell tag for you.

From my personal point of view, I tried to write the following script for your reference.

function Get-DistributionGroupMembers {
    param (
        [string]$GroupName
    )
    $Group = Get-DistributionGroup -Identity $GroupName
    $Members = Get-DistributionGroupMember -Identity $GroupName
    foreach ($Member in $Members) {
        if ($Member.RecipientType -eq 'MailUniversalDistributionGroup' -or $Member.RecipientType -eq 'MailUniversalSecurityGroup') {
            Get-DistributionGroupMembers -GroupName $Member.Name
        } else {
            $Member | Select-Object Name, PrimarySmtpAddress
        }
    }
}
$GroupName = "test1016@****.com"
$Results = Get-DistributionGroupMembers -GroupName $GroupName
$Results | Export-Csv -Path "C:\users\DistributionListMembers.csv" -NoTypeInformation

There is a similar case here for your reference. exchange online : Export list of nested distribution group members in entire forest via powershell in csv format - Microsoft Q&A

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