#$domainRoot = [ADSI]"LDAP://ou=exchange,DC=accounts,DC=domain,DC=local"

$strDate = get-date -uformat "%Y-%m-%d"
$CSVFilePath = 'c:\Users_'+$strDate+'.csv'


$entry = Read-Host "Enter domain scope to search: "

if ($entry -eq '') {
	"going to search the root."
	$root = [ADSI]'LDAP://RootDSE' 
	$entry = $root.DefaultNamingContext.tostring()
	$entry
}


$domainscope = "LDAP://" + $entry
$domainRoot = [ADSI]$domainScope
"Searching: " + $domainRoot
 
# by default this filter finds all disabled mail-enabled users where msExchMasterAccountSID is populated -essentially Linked Mailboxes.
$filter = "(&(objectClass=user)(mailnickname=*)(userAccountControl:1.2.840.113556.1.4.803:=2)(msExchMasterAccountSID=*)(msExchHideFromAddressLists=FALSE))"

# Properties set to variables for the get-mailbox cmdlets below
$proplist = @("distinguishedName","displayName","mailnickname") 

"got to here"

"Display Name, Associated External Account, SendAs Users" | out-file -filepath $CSVFilePath -encoding ascii


# now find all users in the $domainRoot path specified above and add the write personal information for the linked master account.
# If you do want to search subfolders of the specified OU, change "Subtree" from "OneLevel"

$userFinder = new-object System.DirectoryServices.DirectorySearcher($domainRoot, $filter, $proplist, [System.DirectoryServices.SearchScope]::Subtree)
$userFinder.PageSize = 100
$results = $userFinder.FindAll()
foreach ($result in $results) {
	if ($result.Properties["distinguishedname"][0].StartsWith("CN=SystemMailbox{")) {

		# Skip SystemMailbox objects

	} else {
		
		$thisUserDN = $result.Properties["distinguishedname"][0]
		$useralias = $result.Properties["mailnickname"][0]
	$thisUserDN 
		$MAS = get-mailbox $thisUserDN  
		$DisplayName = $MAS.displayname
		$AEA=$MAS.LinkedMasterAccount
		$arSendAs = $MAS | get-adpermission | select user, extendedrights | where {($_.extendedrights -like 'send-as') -and ($_.user -notlike '*SELF*') -and ($_.user -notlike '*S-1-5*')}
		forEach ($User in $arSendAs) {
			"""" + $DisplayName + """," + $AEA  + "," +  $user.user | out-file -filepath $CSVFilePath -encoding ascii -append  
		}

	}
}