Get-GroupMemberReport

PowerShell script to audit Distribution Lists and Microsoft 365 Groups membership using Microsoft Graph API. Returns transitive (recursive) member counts - including all nested group members.

Why?

  • Get-DistributionGroupMember only returns direct members, not nested
  • Exchange Online cmdlets have pagination timeouts on large tenants
  • Graph API’s Get-MgGroupTransitiveMemberCount solves both problems

Requirements

  • PowerShell 5.1+ or PowerShell 7+
  • Microsoft Graph PowerShell SDK
  • Permissions: Group.Read.All, Directory.Read.All

Usage

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# Distribution Lists only
.\Get-GroupMemberReport.ps1 -DL

# Microsoft 365 Groups only  
.\Get-GroupMemberReport.ps1 -M365

# Both types
.\Get-GroupMemberReport.ps1 -All

# Test mode - first ~100 DLs or M365
.\Get-GroupMemberReport.ps1 -DL/M365 -TestLimit 100

Output

CSV file with columns:

ColumnDescription
PrimarySmtpAddressGroup email address
DisplayNameGroup display name
GroupTypeDL or M365
MembersTotal recursive member count
Emptyyes if 0 members
Size_1_10yes if 1-10 members
Size_11_100yes if 11-100 members
…etc.

Size buckets make it easy to filter and analyze DL distribution in Excel.

How it works

  1. Fetches mail-enabled groups via Graph API
  2. Filters by groupTypes property ([] = DL, ["Unified"] = M365)
  3. Calls Get-MgGroupTransitiveMemberCount for each group
  4. Exports results with size category flags

Get the script

Full source code with usage examples: GitHub