Get-UserMailboxMigrationState.ps1

function Get-UserMailboxMigrationState {
    Param(
        [string]$SamAccountName,
        [int]$CreatedWindow
    )
    
    Add-Type -AssemblyName System.DirectoryServices.AccountManagement
    $DirectoryEntry = [System.DirectoryServices.DirectoryEntry]::New()
    $DirectorySearcher = [System.DirectoryServices.DirectorySearcher]::New($DirectoryEntry)

    $UnwrapProperties = @(
        @{
            N = 'name'
            E = {[string]$_.name}
        },
        @{
            N = 'samaccountname'
            E = {[string]$_.samaccountname}
        },
        @{
            N = 'whencreated'
            E = {[datetime]::Parse($_.whencreated)}
        },
        @{
            N = 'mailnickname'
            E = {[string]$_.mailNickname}
        },
        @{
            N = 'msexchhomeservername'
            E = {[string]$_.msexchhomeservername}
        },
        @{
            N = 'homemdb'
            E = {[string]$_.homemdb}
        },
        @{
            N='legacyexchangedn'
            E={[string]$_.legacyexchangedn}
        }
    )
    $IdentifyMailboxState = @(
        'name',
        'samaccountname',
        'whencreated',
        @{
            N = 'hasmailname'
            E = {[bool]$_.mailNickname}
        }
        @{
            N = 'haslocalmailbox'
            E = {[bool]$_.homemdb}
        },
        @{
            N = 'hascloudmailbox'
            E = {$_.legacyexchangedn -match 'ou=External'}
        }
    )
    $SimplifyState = @(
        'name',
        'samaccountname',
        'whencreated',
        @{
            N='MailboxState'
            E = {-join$(('OnPrem'*$_.haslocalmailbox);('o365'*$_.hascloudmailbox))}
        }
    )

    $UnwrapProperties.n | %{
        [void]$DirectorySearcher.PropertiesToLoad.Add($_)
    }
    $DirectorySearcher.PageSize = 2000


    $QueryWrapper = @('(&',')')
    $ClassUser = "(objectClass=user)(objectCategory=Person)"
    $AccountNameMatch = "(samaccountname=$SamAccountName)"
    $HasMailAlias = "(mailNickname=*)"
    $HasHomeDB = "(homemdb=*)"
    $WhenCreated = "(whenCreated>=1$([datetime]::Now.AddDays(-$CreatedWindow).ToString("yyyyMMddHHmmss.sZ")))"
    $IsEnabled = '(!(userAccountControl:1.2.840.113556.1.4.803:=2))'


    $DirectorySearcher.Filter = $(
        $QueryWrapper[0]
        $ClassUser
        $IsEnabled
        if ($SamAccountName) {
            $AccountNameMatch
        }
        if ($CreatedWindow){
            $WhenCreated
        }
        $QueryWrapper[1]
    ) -join $null
        
    $SearchResults = $DirectorySearcher.FindAll() | ForEach-Object {New-Object PSObject -Property $_.Properties} | select $UnwrapProperties | select $IdentifyMailboxState | select $SimplifyState
    
    $SearchResults
}