Get IIS SMTP Server Relay IP Address List

GetIISSMTPRelayIP.ps1

Function GetIISSmtpRelayIPList {
	param (
		# virtual smtp server name
		[parameter()]
		[string]$smtpName = "SmtpSVC/1",
		# computer name
		[parameter()]
		[string]$computerName = $env:COMPUTERNAME
	)
	
	# Get the IISSmtpServerSetting object using WMI
	$vSmtp = Get-WmiObject -computerName $computerName IISSmtpServerSetting -namespace "ROOT\MicrosoftIISv2" | Where-Object {$_.name -eq $smtpName}

	#Create empty variable to store the IP list
	$AllowedIp = @()

	#iterate through the value of $vSmtp.RelayIpList which is of type 'System.Byte'
	$i=0
	While ($i -lt $vSmtp.RelayIpList.Count) {
		#reconstruct to IP address format
		$AllowedIp += $vSmtp.RelayIpList[$i..($i+3)] -join "."
		$i+=4
	}
	# Skip the first 0 to 19 IP address, those are the defaults.
	$AllowedIp = $AllowedIp[20..($AllowedIp.Count)]
	return $AllowedIp
}