GAL Membership Lists

Use this to get a CSV with all the emails in Exchange Online, including if they are in the GAL or not.

Prerequisites

These commands require the ExchangeOnlineManagement module.

Script

$EXORecipient = Get-EXORecipient -ResultSize Unlimited
 
foreach($recipient in $EXORecipient){
 
    foreach($emailaddress in [array]$recipient.emailaddresses){
 
                ##new hashtable
                $hash = [ordered]@{
                    "DisplayName" = DisplayName
                    "PrimarySmtpAddress" = $recipient.PrimarySmtpAddress
                    "emailaddress" = $emailaddress
                    "HiddenFromAddressListsEnabled" = $recipient.HiddenFromAddressListsEnabled
                    "RecipientTypeDetails" = $recipient.RecipientTypeDetails
                }
 
 
                ##Convert hashtable to PSCustomObject
                $obj = New-Object -TypeName psobject -Property $hash
 
                ##Export to CSV
                $obj | Export-Csv -Path "C:\Temp\AllEmailAddresses.csv" -Append -NoTypeInformation
    }
}

More Information

This was adapted from a script written by Sean McAvinue. The original can be found on his GitHub