export mail contact mail user and external contacts

Question

Hi All,

I have distribution lists (DLs) created in both Exchange Online and Exchange On-Premises. These DLs include mail contacts, mail users, and external users. Some DLs are created in Exchange Online, while others are created in Exchange On-Premises.

I want to export all the DLs that contain mail contacts, mail users, or external users to a CSV file so that I can remove them from the DLs.

Could you please help me with a PowerShell script to fetch this information from both DLs and Unified Groups?

Answer 1

Hi @Glenn Maxwell ,

Welcome to the Microsoft Q&A platform!

Below is a PowerShell script that you can use to fetch distribution lists (DLs) containing mail contacts, mail users, or external users from both Exchange Online and Exchange On-Premises, and export the information to a CSV file.

For Exchange Online:

1. Connect to Exchange Online:

$UserCredential = Get-Credential
Connect-ExchangeOnline -UserPrincipalName $UserCredential.UserName -Password $UserCredential.Password

2. Fetch DLs and export to CSV:

$DLs = Get-DistributionGroup -ResultSize Unlimited
$DLsWithExternalUsers = @()

foreach ($DL in $DLs) {
    $Members = Get-DistributionGroupMember -Identity $DL.Identity
    foreach ($Member in $Members) {
        if ($Member.RecipientType -eq 'MailContact' -or $Member.RecipientType -eq 'MailUser' -or $Member.ExternalEmailAddress) {
            $DLsWithExternalUsers += [PSCustomObject]@{
                GroupName = $DL.DisplayName
                MemberName = $Member.DisplayName
                MemberType = $Member.RecipientType
            }
        }
    }
}

$DLsWithExternalUsers | Export-Csv -Path "C:\DLsWithExternalUsers_ExchangeOnline.csv" -NoTypeInformation

For Exchange On-Premises:

Open Exchange Management Shell and run:

$DLs = Get-DistributionGroup -ResultSize Unlimited
$DLsWithExternalUsers = @()

foreach ($DL in $DLs) {
    $Members = Get-DistributionGroupMember -Identity $DL.Identity
    foreach ($Member in $Members) {
        if ($Member.RecipientType -eq 'MailContact' -or $Member.RecipientType -eq 'MailUser' -or $Member.ExternalEmailAddress) {
            $DLsWithExternalUsers += [PSCustomObject]@{
                GroupName = $DL.DisplayName
                MemberName = $Member.DisplayName
                MemberType = $Member.RecipientType
            }
        }
    }
}

$DLsWithExternalUsers | Export-Csv -Path "C:\DLsWithExternalUsers_ExchangeOnPremises.csv" -NoTypeInformation

For Unified Groups (Office 365 Groups):

1. Connect to Exchange Online:

$UserCredential = Get-Credential
Connect-ExchangeOnline -UserPrincipalName $UserCredential.UserName -Password $UserCredential.Password

2. Fetch Unified Groups and export to CSV:

$UnifiedGroups = Get-UnifiedGroup -ResultSize Unlimited
$UnifiedGroupsWithExternalUsers = @()

foreach ($Group in $UnifiedGroups) {
    $Members = Get-UnifiedGroupLinks -Identity $Group.Identity -LinkType Members
    foreach ($Member in $Members) {
        if ($Member.RecipientType -eq 'MailContact' -or $Member.RecipientType -eq 'MailUser' -or $Member.ExternalEmailAddress) {
            $UnifiedGroupsWithExternalUsers += [PSCustomObject]@{
                GroupName = $Group.DisplayName
                MemberName = $Member.DisplayName
                MemberType = $Member.RecipientType
            }
        }
    }
}

$UnifiedGroupsWithExternalUsers | Export-Csv -Path "C:\UnifiedGroupsWithExternalUsers.csv" -NoTypeInformation

This script will help you identify and export the distribution lists and unified groups containing mail contacts, mail users, or external users to CSV files.

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Please feel free to contact me for any updates. And if this helps, don't forget to mark it as an answer.

Best,

Jake Zhang