Get-Mailprotection

1.10

Get-Mailprotection.ps1

###############################################################################
# Get-Mailprotection.ps1
# Andres Bohren / www.icewolf.ch / blog.icewolf.ch / info@icewolf.ch
#
# Version 1.0 / 21.02.2015 Initial Version
# Version 1.1 / 08.04.2015 IDN Domains / Crawled Domains / Unique Domains
# Version 1.2 / 13.04.2015 STARTTLS Support
# Version 1.3 / 26.08.2022 Addet BIMI / DANE / MTA-STS / M365 Checks
# Version 1.4 / 03.10.2022 Addet Reverse Lookup of MX Records / CAA Lookup / TLS-RPT Lookup
# Version 1.5 / 13.10.2022 Fixed Lyncdiscover / Added NS Records & Autodiscover / Minor fixes
# Version 1.6 / 03.04.2023 Addet Parameter -SMTPConnect [true/false] and -ReturnObject [false/true] that is now a PSCustomObject
# Version 1.7 / 16.05.2023 Fixed Lyncdiscover CNAME
# Version 1.8 / 30.09.2023 - Andres Bohren
# - Fixed ReturnObject Nameserver
# - Changed MTA-STSAvailable to MTA-STSAvailable and MTA-STSWeb to MTASTSWeb in ReturnObject
# - ReturnObject of MTASTSWeb is now String
# - ReturnObject of TLSRPT is now String
# - ReturnObject of MXIP is now Array
# - ReturnObject of CAA is now Array
# Version 1.9 / 29.10.2023 - Andres Bohren
# - Fixed Error in Nameserver Output
# - Improved SMTP Connect
# - Addet SMTPBanner
# - Addet SMTPCertificateIssuer
# - Fixed Errorhandling in DANE and NS Lookups
# - Better Errorhandling in SMTPConnect
# - Fixed Autodiscover Lookup
# - Fixed Lyncdiscover Lookup
# - General cleanup of Code
# - Added Security.txt https://securitytxt.org/
# - Added -Silent Parameter
# Version 1.10
# - Fixed STARTTLS and STARTTLS Support in Output and ReturnValue
# Backlog / Whishlist
# - SPF Record Lookup check if max 10 records are used
# - Open Mail Relay Check
# - Parameter for DKIM Selector
###############################################################################

<#PSScriptInfo
.VERSION 1.10
.GUID 3bd03c2d-6269-4df1-b8e5-216a86f817bb
.AUTHOR Andres Bohren Contact: a.bohren@icewolf.ch https://twitter.com/andresbohren
.COMPANYNAME icewolf.ch
.COPYRIGHT Free to copy, inspire, etc...
.TAGS DNSSEC, MX, Reverse Lookup, STARTTLS, SPF, DKIM, DMARC, DANE, MTA-STS, TLS-RPT, BIMI, CAA, M365, TenantID, Security.txt
.LICENSEURI
.PROJECTURI https://github.com/BohrenAn/GitHub_PowerShellScripts/tree/main/Mailprotection
.ICONURI
.EXTERNALMODULEDEPENDENCIES
.REQUIREDSCRIPTS
.EXTERNALSCRIPTDEPENDENCIES
.RELEASENOTES
Version 1.10
- Fixed STARTTLS and STARTTLS Support in Output and ReturnValue
#>

<#
.SYNOPSIS
Script written by Andres Bohren https://blog.icewolf.ch / a.bohren@icewolf.ch
 
This Script checks diffrent DNS Records about a Domain - mostly about Mailsecurity Settings.
It checks for the following Information
- DNS Zone Signed (DNSSEC)
- NS (Nameserver)
- CAA (Certification Authority Authorization)
- MX (MailExchanger)
- MX IP
- MX Reverse Lookup
- Connects to the MX Servers and checks for STARTTLS and shows SMTP Banner and Certificate Information
- SPF (Sender Policy Framework)
- DKIM (DomainKeys Identified Mail)
- DMARC (Domain-based Message Authentication, Reporting and Conformance)
- DANE (DNS-based Authentication of Named Entities)
- BIMI (Brand Indicators for Message Identification)
- MTA-STS (SMTP MTA Strict Transport Security)
- MTA-STS Web (https://mta-sts.domain.tld/.well-known/mta-sts.txt)
- TLS-RPT (TLS Reporting)
- Autodiscover (Outlook)
- Lyncdiscover
- Lync/Skype/Teamsfederation
- M365 (Check via Open ID Connect)
- M365 TenantID
- Security.txt https://securitytxt.org/
 
.DESCRIPTION
This Script checks diffrent DNS Records about a Domain - mostly about Mailsecurity Settings.
Most of the Querys are simple DNS Querys (NS, MX, SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT).
The Script uses also DNS over HTTP for several checks (ZoneSigned, TLSA Record for DANE).
Also some Webrequests are required for MTA-STS, TenantID (OIDC), Security.txt.
And connects via SMTP to check if the Server supports STARTTLS.
 
.NOTES
Note that DKIM is hard to query, because the Selector can be literally anything.
 
.LINK
Script is published here:
https://github.com/BohrenAn/GitHub_PowerShellScripts/tree/main/Mailprotection
 
.EXAMPLE
Get-Mailprotection.ps1 -Domain icewolf.ch
$Result = Get-Mailprotection.ps1 -Domain icewolf.ch -ReturnObject $True
$Result = Get-Mailprotection.ps1 -Domain icewolf.ch -SMTPConnect $False -ReturnObject $True
 
.PARAMETER Domain
Mandatory Parameter. You need to specify a Domain as a string Value
domain.tld or subdomain.domain.tld
 
.PARAMETER SMTPConnect
Optional Parameter. You can specify not to connect with SMTP to the Server. Per Default this Setting is TRUE.
You add the Parameter -SMTPConnect $False
 
.PARAMETER ReturnObject
Optional Parameter. You can specify if a the Script returns an Object (For Scripting purposes). Per Default this Setting is FALSE.
You can add the Parameter -ReturnObject $True
 
.PARAMETER Silent
Optional Parameter. You can specify to not get an Output to the Console. Per Default this Setting is FALSE.
You can add the Parameter -Silent $True.
Can be helpful if you use it with the -ReturnObject $True
#>


PARAM (
    [Parameter(Mandatory=$true)][String]$Domain,
    [Parameter(Mandatory=$false)][bool]$SMTPConnect = $True,
    [Parameter(Mandatory=$false)][bool]$ReturnObject = $false,
    [Parameter(Mandatory=$false)][bool]$Silent = $false
    )

    ###############################################################################
    # Function Invoke-STARTTLS
    ###############################################################################
    # Connect to SMTP Server, check for STARTTLS and then get the Certificate
    # Based on Code from Glen Scales
    # https://github.com/gscales/Powershell-Scripts/blob/master/TLS-SMTPMod.ps1
    # 29.06.2021 V1.0 Andres Bohren - Initial Version
    # 02.08.2022 V1.1 Thomas Nolte - Add optonal ignoring of certifcation errors
    # 01.10.2022 V1.2 Andres Bohren - Fixed an error when connection was not sucessful
    ###############################################################################
    Function Invoke-STARTTLS
    {
        PARAM (
            [Parameter(Mandatory=$true)][String]$SMTPServer
            )

        [bool]$TLSSupport = $false
        $Port = "25"
        #$Sendingdomain = "mail.icewolf.ch"
        $Sendingdomain = "$env:computername.$env:userdnsdomain"
    try {
            If ($Silent -ne $True)
            {
                Write-Host("Connect $SMTPServer $Port") -ForegroundColor Magenta
            }
            $socket = new-object System.Net.Sockets.TcpClient($SMTPServer, $Port)
            $stream = $socket.GetStream()
            $streamWriter = new-object System.IO.StreamWriter($stream)
            $streamReader = new-object System.IO.StreamReader($stream)
            $stream.ReadTimeout = 500
            $stream.WriteTimeout = 500
            $streamWriter.AutoFlush = $true

            $Callback = {param($sender,$cert,$chain,$errors) return $true}
            $sslStream = New-Object System.Net.Security.SslStream($stream, $false, $Callback)

            $sslStream.ReadTimeout = 500
            $sslStream.WriteTimeout = 500
            $ConnectResponse = $streamReader.ReadLine();
            If ($Silent -ne $True)
            {
                Write-Host($ConnectResponse)
            }
            if(!$ConnectResponse.StartsWith("220")){
                #throw "Error connecting to the SMTP Server"
            } else {
                $SMTPBanner = $ConnectResponse
            }

            #Send "EHLO"
            If ($Silent -ne $True)
            {
                Write-Host(("EHLO " + $Sendingdomain)) -ForegroundColor Magenta
            }
            $streamWriter.WriteLine(("EHLO " + $Sendingdomain));

        } catch {
            If ($Silent -ne $True)
            {
                Write-Host "ERROR $_"
            }
        }

        $response = @()
        Try {
            while($streamReader.EndOfStream -ne $true)
            {
                    $ehloResponse = $streamReader.ReadLine();
                    If ($Silent -ne $True)
                    {
                        Write-Host($ehloResponse)
                    }
                    $response += $ehloResponse
            }
        } catch {

            If ($response -match "STARTTLS")
            {
                    $TLSSupport = $true

                    #StartTLS found
                    If ($Silent -ne $True)
                    {
                        Write-Host("STARTTLS") -ForegroundColor Magenta
                    }

                    $streamWriter.WriteLine("STARTTLS");
                    $startTLSResponse = $streamReader.ReadLine();
                    If ($Silent -ne $True)
                    {
                        Write-Host($startTLSResponse)
                    }

                    #Get Certificate
                    $ccCol = New-Object System.Security.Cryptography.X509Certificates.X509CertificateCollection
                    $sslStream.AuthenticateAsClient($ServerName,$ccCol,[System.Security.Authentication.SslProtocols]::Tls12,$false)
                    $Cert = $sslStream.RemoteCertificate.Export([System.Security.Cryptography.X509Certificates.X509ContentType]::Cert)

                    #Show Certificate Details
                    If ($Silent -ne $True)
                    {
                        Write-Host "Certificate Details:" -ForegroundColor Green
                        Write-Host "Issuer: $($sslStream.RemoteCertificate.Issuer)"
                        Write-Host "Subject: $($sslStream.RemoteCertificate.Subject)"
                        Write-Host "ValidFrom: $($sslStream.RemoteCertificate.GetEffectiveDateString())"
                        Write-Host "ValidTo: $($sslStream.RemoteCertificate.GetExpirationDateString())"
                        Write-Host "SerialNumber: $($sslStream.RemoteCertificate.GetSerialNumberString())"
                        Write-Host "Thumbprint: $($sslStream.RemoteCertificate.GetCertHashString())"
                    }

                    $SMTPCertIssuer = $sslStream.RemoteCertificate.Issuer

                    $stream.Dispose()
                    $sslStream.Dispose()

            } else {
                If ($Silent -ne $True)
                {
                    Write-Host "ERROR: No <STARTTLS> found" -ForegroundColor Yellow
                }
                [bool]$TLSSupport = $false
            }
        }

        $ResultObject = [PSCustomObject]@{}
        $ResultObject | Add-Member -MemberType NoteProperty -Name 'SMTPBanner' -Value $SMTPBanner
        $ResultObject | Add-Member -MemberType NoteProperty -Name 'SMTPCertIssuer' -Value $SMTPCertIssuer
        $ResultObject | Add-Member -MemberType NoteProperty -Name 'TLSSupport' -Value $TLSSupport

        return $ResultObject
        #return $TLSSupport
    }

###############################################################################
# Function Get-MailProtection
###############################################################################
Function Get-MailProtection
{
    [cmdletbinding()]
    PARAM (
    [Parameter(Mandatory=$true)][String]$Domain,
    [Parameter(Mandatory=$false)][Bool]$SMTPConnect
    )

    [bool]$ZoneDNSSigned = $false
    [bool]$MXAvailable = $False
    [int]$MXCount = 0
    $MXReverseLookup = $Null
    [int]$StartTLSCount = 0
    [bool]$SPFAvailable = $False
    [bool]$DomainKeyAvailable = $False
    [String]$DomainKeySupport = "None"
    [bool]$DMARCAvailable = $False
    [int]$DANECount = 0
    [bool]$DANEAvailable = $false
    [string]$DANESupport = "None"
    [bool]$M365 = $False
    [bool]$BIMIAvailable = $False
    [string]$BIMIRecord = $Null
    [bool]$MTASTSAvailable = $false

    ## Check if DNS Zone is signed
    If ($Silent -ne $True)
    {
        Write-Host "Check: DNS Zone Signed" -ForegroundColor Green
    }
    $URI = "https://dns.google/resolve?name=$Domain&type=NS"
    $json = Invoke-RestMethod -URI $URI
    If ($json.ad -eq "True")
    {
        $ZoneDNSSigned = $true
    }

    ## Nameserver (NS)
    $Nameserver = $Null
    $NS = Resolve-DnsName -Type NS $Domain -ErrorAction SilentlyContinue
    If ($null -ne $NS)
    {
        [Array]$Nameserver = $NS.NameHost
    }

    ## CAA
    If ($Silent -ne $True)
    {
        Write-Host "Check: CAA" -ForegroundColor Green
    }
    #https://de.wikipedia.org/wiki/DNS_Certification_Authority_Authorization
    #$Domain = "iis.se"
    $CAA = $Null
    $json = Invoke-RestMethod -URI "https://dns.google/resolve?name=$Domain&type=CAA"
    If ($Null -ne $json.Answer.Data)
    {
        [Array]$CAA = $json.Answer.Data # ($json.Answer.Data | Out-String).Trim()
    }

    ##Check for MX Record
    If ($Silent -ne $True)
    {
        Write-Host "Check: MX" -ForegroundColor Green
    }
    $MX = Resolve-DnsName -Name $Domain -Type MX -ErrorAction SilentlyContinue
    [Array]$MXRecord = $MX.NameExchange #($mx.nameExchange | Out-String).Trim()
    If ($NULL -eq $MXRecord -or $MXRecord -eq "" -or $MXRecord -eq $False)
    {
        $MXRecord = $NULL
    }

    $DANERecord = $NULL
    Foreach ($MXEntry in $MX)
    {
        If ($Null -ne $MXEntry.NameExchange)
        {
            #MX Found
            $MXAvailable = $true
            $MXCount = $MXCount + 1

            #ReverseLookup
            $MXIP = Resolve-DnsName $MXEntry.NameExchange -ErrorAction SilentlyContinue | Where-Object {$_.Type -eq "A"}
            Foreach ($IP in $MXIP.IPAddress)
            {
                [Array]$MXIPArray += $IP
                $ReverseLookupName = Resolve-DnsName $IP -ErrorAction SilentlyContinue
                If ($Null -ne $ReverseLookupName)
                {
                    [Array]$MXReverseLookup += $ReverseLookupName.NameHost
                }
            }

            #StartTLS
            #Only Connect if Parameter $SMTPConnect is True (default)
            If ($SMTPConnect -eq $True)
            {
                If ($Silent -ne $True)
                {
                    Write-Host "Check: SMTPConnect" -ForegroundColor Green
                }
                #$TestConnection = Test-NetConnection $MXEntry.NameExchange -Port 25
                #If ($TestConnection.TcpTestSucceeded -eq $true)
                try {
                    $tcpClient = New-Object System.Net.Sockets.TcpClient
                    $portOpened = $tcpClient.ConnectAsync("mail.icewolf.ch", "25").Wait(1000)
                } catch {
                    $PortOpened = $false
                }
                #$PortOpened

                If ($PortOpened -eq $true)
                {
                    If ($Silent -ne $True)
                    {
                        Write-Host "Check: StartTLS" -ForegroundColor Green
                    }
                    $StartTLSReturn = Invoke-STARTTLS -SMTPServer $MXEntry.NameExchange
                    [Array]$SMTPBannerArray += $StartTLSReturn.SMTPBanner
                    [Array]$SMTPCertIssuerArray += $StartTLSReturn.SMTPCertIssuer
                }
            }
            If ($StartTLSReturn.TLSSupport -eq $true)
            {
                $StartTLSCount = $StartTLSCount + 1
            }

            try {

            #DANE
            If ($Silent -ne $True)
            {
                Write-Host "Check: DANE" -ForegroundColor Green
            }
            $TLSAQuery = "_25._tcp.$($MXEntry.NameExchange)"
            #$URL= "https://dns.google/resolve?name=$TLSAQuery&type=TLSA"
            #Write-Host "DEBUG: TLSAQuery: $TLSAQuery" -ForegroundColor magenta
            #Write-Host "DEBUG: URI https://dns.google/resolve?name=$TLSAQuery&type=TLSA" -ForegroundColor magenta

            $json = $Null
            $json = Invoke-RestMethod -URI "https://dns.google/resolve?name=$TLSAQuery&type=TLSA"

            } catch {
                If ($Silent -ne $True)
                {
                    Write-Host "StatusCode:" $_.Exception.Response.StatusCode.value__ -ForegroundColor Yellow
                    Write-Host "StatusDescription:" $_.Exception.Response.StatusDescription -ForegroundColor Yellow
                    Write-Host "Query:" $TLSAQuery -ForegroundColor Yellow
                }
            } 
            If ($null -ne $json.Answer.data)
            {
                #DANE Found
                $TLSA = $json.Answer.data
                #$TLSA
                $DANEAvailable = $true
                $DANECount = $DANECount + 1
                $DANERecord = $DANERecord + $TLSA
            }
            
        }
    }

    #Check if all MX support StartTLS
    If ($Silent -ne $True)
    {
        Write-Host "Check: StartTLS Support" -ForegroundColor Green
    }
    If ($MXCount -gt 0)
    {
        If ($MXCount -eq $StartTLSCount)
        {
            #All Mailserver in MX Records support STARTTLS
            $StartTLSSupport = "All"
        }
        If ($MXCount -gt $StartTLSCount)
        {
            #Some Mailserver in MX Records support STARTTLS
            $StartTLSSupport = "Some"
        }
        If ($StartTLSCount -eq 0)
        {
            #None Mailserver in MX Records support STARTTLS
            $StartTLSSupport = "None"
        }
    }

    #Check if all MX support DANE
    If ($MXCount -gt 0)
    {
        If ($MXCount -eq $DANECount)
        {
            #All Mailserver in MX Records support DANE
            $DANESupport = "All"
        }
        If ($MXCount -gt $DANECount)
        {
            #Some Mailserver in MX Records support DANE
            If ($DANECount -gt 0)
            {
                $DANESupport = "Some"
            } else {
                $DANESupport = "None"
            }
        }
        If ($StartTLSCount -eq 0)
        {
            #None Mailserver in MX Records support DANE
            $DANESupport = "None"
        }
    }

    ## SPF
    If ($Silent -ne $True)
    {
        Write-Host "Check: SPF" -ForegroundColor Green
    }
    $SPFRecord = $Null
    $TXT = Resolve-DnsName -Name $Domain -Type TXT -ErrorAction SilentlyContinue
    $SPFRecord = $TXT.strings -match "v=spf"
    If ($SPFRecord -eq $false -or $NULL -eq $SPFRecord) 
    {
        $SPFRecord = $NULL
    } else {
        #SPF Record Presend
        If ($SPFRecord.Count -eq 1)
        {
            [string]$SPFRecord = ($SPFRecord | Out-String).Replace("'","").Trim()            
        } else {
            $SPFRecord = "MULTIPLE SPF RECORDS"
        }
    }

    Foreach ($TXTEntry in $TXT)
    {
        If ($TXTEntry.Strings -match "v=spf" -or $TXTEntry.Strings-match "spf2.0")
        {
            #SPF Found
            $SPFAvailable = $true
        }
    }

    ## Check for DomainKey / DKIM
    If ($Silent -ne $True)
    {
        Write-Host "Check: DKIM" -ForegroundColor Green
    }
    $DomainKeyRecord = $Null
    $DomainKeySupport = $False
    $dnshost = "_domainkey." + $Domain
    $Domainkey = Resolve-DnsName -Name $dnshost -Type TXT -ErrorAction SilentlyContinue
    Foreach ($Key in $DomainKey)
    {
        If ($Null -ne $KEY.Strings)
        {
            #DomainKey Found
            $DomainKeyAvailable = $true
            $DomainKeySupport = $True
            $DomainKeyRecord = $KEY.Strings
        }
    }
    #Try O365 Selector1 and Selector2
    If ($DomainKeyAvailable -eq $false)
    {
        $dnshost1 = "selector1._domainkey." + $Domain
        $dnshost2 = "selector2._domainkey." + $Domain
        $DomainkeyS1 = Resolve-DnsName -Name $dnshost1 -Type CNAME -ErrorAction SilentlyContinue
        $DomainkeyS2 = Resolve-DnsName -Name $dnshost2 -Type CNAME -ErrorAction SilentlyContinue
        If ($Null -ne $DomainkeyS1.NameHost -or $Null -ne $DomainkeyS2.NameHost)
        {
            $DomainKeySupport = $True
            $DomainKeyAvailable = $True
            [Array]$DomainKeyRecord += $DomainkeyS1.NameHost
            [Array]$DomainKeyRecord += $DomainkeyS2.NameHost
        }
    }
     #If DomainKey TXT is not Available check NS
    If ($DomainKeyAvailable -eq $false)
    {
        #If DomainKey TXT is not Available check NS
        $DomainkeyNS = Resolve-DnsName -Name $dnshost -Type NS -ErrorAction SilentlyContinue
        If ($Null -ne $DomainkeyNS)
        {
            $DomainKeySupport = "maybe"
        }
}

    ## Check for DMARC
    If ($Silent -ne $True)
    {
        Write-Host "Check: DMARC" -ForegroundColor Green
    }
    $DMARCRecord = $Null 
    $dnshost = "_dmarc." + $Domain
    #Write-Host "DNSHOST: " $dnshost
    $DMARC = Resolve-DnsName -Name $dnshost -Type TXT -ErrorAction SilentlyContinue
    Foreach ($DMARCEntry in $DMARC)
    {
        #If ($DMARCEntry.Strings -match "v=DMARC1")
        If ($DMARCEntry.Strings -like "v=DMARC1*")
        {
            #DMARC Found
            $DMARCRecord = ($DMARCEntry.Strings).Replace("'","")
            $DMARCAvailable = $true
        }
    }

    ## BIMI
    If ($Silent -ne $True)
    {
        Write-Host "Check: BIMI" -ForegroundColor Green
    }
    #default._bimi.example.com in txt
    #"v=BIMI1; l=https://www.example.com/path/to/logo/example.svg; a=https://www.example.com/path/to/vmc/VMC.pem;"
    $dnshost = "default._bimi." + $Domain
    $BIMI = Resolve-DnsName -Name $dnshost -Type TXT -ErrorAction SilentlyContinue
    Foreach ($BIMIEntry in $BIMI)
    {
        If ($BIMIEntry.Strings -match "v=BIMI1;")
        {
            #BIMI Found
            $BIMIAvailable = $true
            [String]$BIMIRecord = $BIMIEntry.Strings -Join " "
        }
    }

    ## MTA STS
    If ($Silent -ne $True)
    {
        Write-Host "Check: MTA-STS" -ForegroundColor Green
    }
    #mta-sts.domain.de/.well-known/mta-sts.txt
    #https://mta-sts.dmarcian.com/.well-known/mta-sts.txt
    #$Domain = "dmarcian.com"
    #$Domain = "google.com"
    #$Domain = "icewolf.ch"
    $DNSHost = "_mta-sts." + $Domain
    $MTASTS = Resolve-DnsName -Name $DNSHost -Type TXT -ErrorAction SilentlyContinue
    Foreach ($MTASTSEntry in $MTASTS)
    {
        If ($MTASTSEntry.Strings -match "v=STSv1")
        {
            #MTA-STS Found
            $MTASTSAvailable = $true
            #Write-Host "MTA STS Found" -ForegroundColor Green

            $URI = "https://mta-sts.$Domain/.well-known/mta-sts.txt"
            try {
                $Response = Invoke-WebRequest -URI $URI -TimeoutSec 1
                $MTASTSTXT = ($response.Content).trim().Replace("`r`n","")
            #$MTASTSTXT
            } catch {
                If ($Silent -ne $True)
                {
                    Write-Host "An exception was caught: $($_.Exception.Message)" -ForegroundColor Yellow
                }
            }
        } else {
            $MTASTSAvailable = $False
        }
    }

    ## TLS-RPT
    #_smtp._tls.google.com IN TXT "{v=TLSRPTv1;rua=mailto:sts-reports@google.com}"
    If ($Silent -ne $True)
    {
        Write-Host "Check: TLS-RPT" -ForegroundColor Green
    }
    $TLSRPTQuery = "_smtp._tls.$Domain"
    $TLSRPT = Resolve-DnsName -Name $TLSRPTQuery -Type TXT -ErrorAction SilentlyContinue
    If ($Null -ne $TLSRPT)
    {
        [String]$TLSRPTRecord = $TLSRPT.Strings
    }

    ## Autodiscover
    #AutodiscoverV2
    #$URI = "https://autodiscover.icewolf.ch/autodiscover/autodiscover.json/v1.0/info@$domain?Protocol=AutodiscoverV1"
    If ($Silent -ne $True)
    {
        Write-Host "Check: Autodiscover" -ForegroundColor Green
    }
    [array]$Autodiscover = Resolve-DnsName -Name autodiscover.$Domain -ErrorAction SilentlyContinue | Where-Object {$_.Type -eq "CNAME" -or $_.Type -eq "A"}
    If ($Null -ne $Autodiscover)
    {
        $AutodiscoverCNAME = $Autodiscover[0] | Where-Object {$_.Type -eq "CNAME"}
        If ($NULL -ne $AutodiscoverCNAME)
        {
            [string]$Autodiscover = ($AutodiscoverCNAME | Select-Object NameHost -Unique).NameHost
        } else {
            $AutodiscoverA = $Autodiscover[0] | Where-Object {$_.Type -eq "A"}
            If ($NULL -ne $AutodiscoverA)
            {
                [string]$Autodiscover = ($AutodiscoverA | Select-Object IPAddress -Unique).IPAddress
            }
        }
        If ($Null -eq $Autodiscover)
        {
            $SRV = Resolve-DnsName _autodiscover._tcp.$Domain -Type SRV -ErrorAction SilentlyContinue
            $Autodiscover = ($SRV.NameTarget | Out-String).Trim()
        }
    } 

    ## LyncDiscover
    If ($Silent -ne $True)
    {
        Write-Host "Check: Lyncdiscover" -ForegroundColor Green
    }
    $Lyncdiscover = Resolve-DnsName lyncdiscover.$Domain -ErrorAction SilentlyContinue | Where-Object {$_.Type -eq "CNAME" -or $_.Type -eq "A"}
    $LyncdiscoverCNAME = $Lyncdiscover | Where-Object {$_.Type -eq "CNAME"}
    If ($NULL -ne $LyncdiscoverCNAME)
    {
        $Lyncdiscover = ($LyncdiscoverCNAME | Select-Object Name,NameHost -Unique).NameHost
    } else {
        $LyncdiscoverA = $Lyncdiscover | Where-Object {$_.Type -eq "A"}
        If ($NULL -ne $LyncDiscoverA)
        {
            $Lyncdiscover = ($LyncdiscoverA | Select-Object Name -Unique).name
        }
    }
    If ($Lyncdiscover -eq "" -or $Null -eq $Lyncdiscover)
    {
        #$Lyncdiscover = "NULL"
        $Lyncdiscover = $Null
    }

    ## Skype4B / Teams Federation
    If ($Silent -ne $True)
    {
        Write-Host "Check: Skype4B / Teams Federation" -ForegroundColor Green
    }
    $SRV = Resolve-DnsName _sipfederationtls._tcp.$Domain -Type SRV -ErrorAction SilentlyContinue
    $SkypeFederation = ($SRV.NameTarget | Out-String).Trim()
    If ($SkypeFederation -eq "" -or $Null -eq $SkypeFederation)
    {
        #$SkypeFederation = "NULL"
        $SkypeFederation = $Null
    }

    ## M365
    If ($Silent -ne $True)
    {
        Write-Host "Check: M365 Tenant (OpenIDConnect)" -ForegroundColor Green
    }
    try {
        #$TenantID = (Invoke-WebRequest -UseBasicParsing https://login.windows.net/$($Domain)/.well-known/openid-configuration|ConvertFrom-Json).token_endpoint.Split('/')[3]
        $Response = Invoke-WebRequest -UseBasicParsing https://login.windows.net/$($Domain)/.well-known/openid-configuration -TimeoutSec 1
        $TenantID = ($Response | ConvertFrom-Json).token_endpoint.Split('/')[3]
        $M365 = $True 

    } catch {
        If ($Silent -ne $True)
        {
            Write-Host "An exception was caught: $($_.Exception.Message)" -ForegroundColor Yellow
        }
        #$TenantID = "NULL"
        $TenantID = $Null
        $M365 = $False 
    }

    ## Check for https://securitytxt.org/
    # Example: https://www.admin.ch/.well-known/security.txt
    If ($Silent -ne $True)
    {
        Write-Host "Check: security.txt" -ForegroundColor Green
    }

    [bool]$SecurityTXTAvailable = $false
    $URI = "https://$Domain/.well-known/security.txt"
    try {
        $Response = Invoke-WebRequest -URI $URI -TimeoutSec 1
        If ($Null -ne $Response)
        {
            [bool]$SecurityTXTAvailable = $true
        }
    } catch {
        If ($Silent -ne $True)
        {
            Write-Host "An exception was caught: $($_.Exception.Message)" -ForegroundColor Yellow
        }
    }

    $URI = "https://$Domain/security.txt"
    try {
        $Response = Invoke-WebRequest -URI $URI -TimeoutSec 1
        If ($Null -ne $Response)
        {
            [bool]$SecurityTXTAvailable = $true
        }
    } catch {
        If ($Silent -ne $True)
        {
            Write-Host "An exception was caught: $($_.Exception.Message)" -ForegroundColor Yellow
        }
    }

    # Convert Arrays to String
    $MXIPString = $MXIPArray -join " "
    If ($Null -ne $Nameserver -or $Nameserver -ne "")
    {
        $NameserverString = $Nameserver -Join " "
    }

    [String]$SMTPBanner = ""
    If ($Null -ne $SMTPBannerArray)
    {
        $SMTPBanner = $SMTPBannerArray -join " "
    }

    [String]$SMTPCertIssuer = ""
    If ($Null -ne $SMTPCertIssuerArray)
    {
        $SMTPCertIssuer = $SMTPCertIssuerArray -join " "
    }

    #Write Output
    If ($Silent -ne $True)
    {
        Write-Host "SUMMARY: $Domain" -ForegroundColor cyan
        Write-Host "Nameserver:" $NameserverString -ForegroundColor cyan
        Write-Host "Zone DNS Signed: $ZoneDNSSigned" -ForegroundColor cyan
        Write-Host "Certification Authority Authorization (CAA): $CAA" -ForegroundColor cyan
        Write-Host "MXCount: $MXCount" -ForegroundColor cyan
        Write-Host "MXRecord: $MXRecord" -ForegroundColor cyan
        Write-Host "MXIP: $MXIPString" -ForegroundColor cyan
        Write-Host "MXReverseLookup: $MXReverseLookup" -ForegroundColor cyan
        Write-Host "STARTTLS: $StartTLSCount" -ForegroundColor cyan
        Write-Host "STARTTLS Support: $StartTLSSupport" -ForegroundColor cyan
        Write-Host "SMTPBanner: $SMTPBanner" -ForegroundColor cyan
        Write-Host "SMTPCertIssuer: $SMTPCertIssuer" -ForegroundColor cyan
        Write-Host "SPF: $SPFAvailable" -ForegroundColor cyan
        Write-Host "SPFRecord: $SPFRecord" -ForegroundColor cyan
        Write-Host "DKIM: $DomainKeyAvailable" -ForegroundColor cyan
        Write-Host "DKIM Support: $DomainKeySupport" -ForegroundColor cyan
        Write-Host "DKIM Record: $DomainKeyRecord" -ForegroundColor cyan
        Write-Host "DMARC: $DMARCAvailable " -ForegroundColor cyan
        Write-Host "DMARCRecord: $DMARCRecord" -ForegroundColor cyan
        Write-Host "DANECount: $DANECount" -ForegroundColor cyan
        Write-Host "DANESupport: $DANESupport" -ForegroundColor cyan
        Write-Host "DANERecord: $DANERecord" -ForegroundColor cyan
        Write-Host "BIMI: $BIMIAvailable" -ForegroundColor cyan
        Write-Host "BIMI Record: $BIMIRecord" -ForegroundColor cyan
        Write-Host "MTA-STS: $MTASTSAvailable" -ForegroundColor cyan
        Write-Host "MTA-STS-Web: $MTASTSTXT" -ForegroundColor cyan
        Write-Host "TLS-RPT: $TLSRPTRecord" -ForegroundColor cyan
        Write-Host "Autodiscover: $Autodiscover" -ForegroundColor cyan
        Write-Host "Lyncdiscover: $Lyncdiscover" -ForegroundColor cyan
        Write-Host "SkypeFederation: $SkypeFederation" -ForegroundColor cyan
        Write-Host "M365: $M365" -ForegroundColor cyan
        Write-Host "TenantID: $TenantID" -ForegroundColor cyan
        Write-Host "SecurityTXT: $SecurityTXTAvailable" -ForegroundColor cyan
    }

    #Better ResponseObject
    $ResultObject = [PSCustomObject]@{}
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'Domain' -Value $Domain
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'NameServer' -Value $Nameserver
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'ZoneDNSSigned' -Value $ZoneDNSSigned
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'CAA' -Value $CAA
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'MXCount' -Value $MXCount
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'MXRecord' -Value $MXRecord
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'MXIP' -Value $MXIPArray
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'MXReverseLookup' -Value $MXReverseLookup
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'StartTLSCount' -Value $StartTLSCount
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'StartTLSSupport' -Value $StartTLSSupport
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'SMTPBanner' -Value $SMTPBannerArray
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'SMTPCertIssuer' -Value $SMTPCertIssuerArray
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'SPFAvailable' -Value $SPFAvailable
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'SPFRecord' -Value $SPFRecord
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DomainKeyAvailable' -Value $DomainKeyAvailable
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DomainKeySupport' -Value $DomainKeySupport
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DomainKeyRecord' -Value $DomainKeyRecord
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DMARCAvailable' -Value $DMARCAvailable
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DMARCRecord' -Value $DMARCRecord
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DANECount' -Value $DANECount
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DANESupport' -Value $DANESupport
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'DANERecord' -Value $DANERecord
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'BIMIAvailable' -Value $BIMIAvailable
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'BIMIRecord' -Value $BIMIRecord
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'MTASTSAvailable' -Value $MTASTSAvailable
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'MTASTSWeb' -Value $MTASTSTXT
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'TLSRPT' -Value $TLSRPTRecord
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'Autodiscover' -Value $Autodiscover
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'LyncDiscover' -Value $Lyncdiscover
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'SkypeFederation' -Value $SkypeFederation
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'M365' -Value $M365
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'TenantID' -Value $TenantID
    $ResultObject | Add-Member -MemberType NoteProperty -Name 'SecurityTXT' -Value $SecurityTXTAvailable

    return $ResultObject
}

###############################################################################
# Main Script
###############################################################################
$Result = Get-MailProtection -Domain $Domain -SMTPConnect $SMTPConnect
If ($ReturnObject -eq $true)
{
    $Result
}