Retrieve Email DNS Records

function Get-MailDomainInfo
{
    param(
        [parameter(Mandatory = $true)][string[]]$DomainName,
        [parameter(Mandatory = $false)][string]$DNSserver = '1.1.1.1'
    )

    $info = foreach ($domain in $DomainName)
    {
        #Check if domain name is valid, output warning it not and continue to the next domain (if any)
        try
        {
            Resolve-DnsName -Name $domain -Server $DNSserver -ErrorAction Stop | Out-Null

            #Retrieve all mail DNS records
            $autodiscoverA = (Resolve-DnsName -Name "autodiscover.$($domain)" -Type A -Server $DNSserver -ErrorAction SilentlyContinue).IPAddress
            $autodiscoverCNAME = (Resolve-DnsName -Name "autodiscover.$($domain)" -Type CNAME -Server $DNSserver -ErrorAction SilentlyContinue).NameHost
            $dkim1 = Resolve-DnsName -Name "selector1._domainkey.$($domain)" -Type CNAME -Server $DNSserver -ErrorAction SilentlyContinue
            $dkim2 = Resolve-DnsName -Name "selector2._domainkey.$($domain)" -Type CNAME -Server $DNSserver -ErrorAction SilentlyContinue
            $dmarc = (Resolve-DnsName -Name "_dmarc.$($domain)" -Type TXT -Server $DNSserver -ErrorAction SilentlyContinue | Where-Object Strings -Match 'DMARC').Strings
            $mx = (Resolve-DnsName -Name $domain -Type MX -Server $DNSserver -ErrorAction SilentlyContinue).NameExchange
            $spf = (Resolve-DnsName -Name $domain -Type TXT -Server $DNSserver -ErrorAction SilentlyContinue | Where-Object Strings -Match 'v=spf').Strings
            $includes = (Resolve-DnsName -Name $domain -Type TXT -Server $DNSserver -ErrorAction SilentlyContinue | Where-Object Strings -Match 'v=spf').Strings -split ' ' | Select-String 'Include:'

            #Set variables to Not enabled or found if they can't be retrieved
            $errorfinding = 'Not enabled'

            if ($null -eq $dkim1 -and $null -eq $dkim2)
            {
                $dkim = $errorfinding
            }
            else
            {
                $dkim = "$($dkim1.Name) , $($dkim2.Name)"
            }

            if ($null -eq $dmarc)
            {
                $dmarc = $errorfinding
            }

            if ($null -eq $mx)
            {
                $mx = $errorfinding
            }

            if ($null -eq $spf)
            {
                $spf = $errorfinding
            }

            if ($null -eq $autodiscoverCNAME)
            {
                $autodiscoverCNAME = $errorfinding
            }

            if (($autodiscoverA).count -gt 1 -or $null -ne $autodiscoverCNAME)
            {
                $autodiscoverA = $errorfinding
            }

            if ($null -eq $includes)
            {
                $includes = $errorfinding
            }
            else
            {
                $foundincludes = foreach ($include in $includes)
                {
                    if ((Resolve-DnsName -Server $DNSserver -Name $include.ToString().Split(':')[1] -Type txt -ErrorAction SilentlyContinue).Strings)
                    {
                        [PSCustomObject]@{
                            SPFIncludes = "$($include.ToString().Split(':')[1]) : " + $(Resolve-DnsName -Server $DNSserver -Name $include.ToString().Split(':')[1] -Type txt).Strings
                        }
                    }
                    else
                    {
                        [PSCustomObject]@{
                            SPFIncludes = $errorfinding
                        }
                    }
                }
            }

            [PSCustomObject]@{
                'Domain Name' = $domain
                'Autodiscover IP-Address' = $autodiscoverA
                'Autodiscover CNAME ' = $autodiscoverCNAME
                'DKIM Record' = $dkim
                'DMARC Record' = "$($dmarc)"
                'MX Record(s)' = $mx -join ', '
                'SPF Record' = "$($spf)"
                'SPF Include values' = "$($foundincludes.SPFIncludes)" -replace 'all', "all`n`b"
            }
        }
        catch
        {
            Write-Warning $PSItem
            Write-Warning ('{0} not found' -f $domain)
        }
    }

    return $info
}