# get-mxrecord
#
# get a domain as parameter or a list of domains via pipeline to quest MX-Record
# uses NSLOOKUP to get data ans parse the STDOUT.
# Results are sent to the pipeline
#
# 20121023 FC Initial Version
 
param(
                [Parameter(
                Position=0, Mandatory=$true,HelpMessage="Specify Domain",ValueFromPipeline=$true)][string]$domain,
                [string]$dnsserver
)
 
begin { 
    Write-Host 'get-mxrecord: ============== started ============== '
                $resultlist = @()
}
process {
    Write-Host "get-mxrecord: ------ Processing Data --------"
 
                Write-Host "Start NSLOOKUP für Domain $domain   optional DNSServer:$dnsserver"
                $result =( nslookup.exe -q=MX $domain $dnsserver)
                [Boolean]$msfound = $false
                foreach ($line in $result) {
                               Write-Host "  parsing line$line"
                               if ($line -match ".*MX\spreference\s=\s(\d*),\smail\sexchanger\s=\s(.*)") {
                                               write-host "Found MX-Record Prio:"$matches[1]"  Host:"$Matches[2]
                                               $msfound = $true                          
                                               # send result to pipeline
                                               Write-Host " Adding Result to resultlist"
                                               $resultlist += New-Object PSObject -Property @{
                                                               domain = $domain
                                                               prio = $matches[1]
                                                               host = $matches[2]
                                }
                               }
                }
                if (!$msfound ) {
                               $resultlist += New-Object PSObject -Property @{
                                               domain = $domain
                                               prio = ""
                                               host = "--not found --"
                               }
                }
}
 
end {
                Write-Host " Sending results to output"
                $resultlist 
    Write-Host "get-mxrecord: ==============  ended ============== "
                
}