Get all email addresses in AD

$searchfilter = {
(EmailAddress -like "*") -or
(extensionAttribute14 -like "*") -or
(extensionAttribute15 -like "*") -or
(mail -like "*") -or
(msExchShadowProxyAddresses -like "*") -or
(msRTCSIP-PrimaryUserAddress -like "*") -or
(personalPager -like "*") -or
(proxyAddresses -like "*") -or
(targetAddress -like "*") -or
(UserPrincipalName -like "*")
}
$properties = "SamAccountName","EmailAddress","extensionAttribute14","extensionAttribute15","mail","msExchShadowProxyAddresses","msRTCSIP-PrimaryUserAddress","personalPager","proxyAddresses","targetAddress","UserPrincipalName"
$adusersemails = Get-ADUser -Filter $searchfilter -Properties $properties | select $properties
$results = @()
foreach ($user in $adusersemails) {
    foreach ($singleproperty in $properties) {
        if ($user.($singleproperty) -notlike "") { #iterate through the properties that only have data
            if($user.($singleproperty).GetType().Name -eq "ADPropertyValueCollection") { #if it is a property value collection
                foreach ($collectionitem in $user.($singleproperty)) { #foreach item in the collection
                    if ($collectionitem.Contains("@")) { #if it contains a whir
                        $results += New-Object -TypeName PSObject -Property @{"samaccountname"=$user.SamAccountName;"emailaddress"=$collectionitem.ToLower().Replace("smtp:","").Replace("sip:","")}
                    } #if it contains a whirl
                } #foreachitem in the collection
            } else {
                if ($user.($singleproperty).Contains("@")) { #if it contains a whir
                    $results += New-Object -TypeName PSObject -Property @{"samaccountname"=$user.SamAccountName;"emailaddress"=$user.($singleproperty).ToLower().Replace("smtp:","").Replace("sip:","")}
                } #if it contains a whirl
            } #if else collection or string
        } #if the property has datea
    } #foreach property
} #foreach user
$results = $results | Sort-Object -Property emailaddress | Get-Unique -AsString
$results