tak.Get-DKIMRecord.ps1

function Get-DKIMRecord {
    <#
    .SYNOPSIS
        Get DKIM Record for a domain.
    .DESCRIPTION
        This function uses Resolve-DNSName to get the DKIM Record for a given domain. Objects with a DomainName property,
        such as returned by Get-AcceptedDomain, can be piped to this function. The function defaults to "selector1" as this
        is typically used with Exchange Online.
    .EXAMPLE
        Get-AcceptedDomain | Get-DKIMRecord
 
        This example gets DKIM records for all domains returned by Get-AcceptedDomain.
    #>

    [CmdletBinding(HelpUri = 'https://ntsystems.it/PowerShell/TAK/Get-DKIMRecord/')]
    param (
        # Specify the Domain name to use in the query.
        [Parameter(Mandatory=$true,
            ValueFromPipelineByPropertyName=$true,
            ValueFromPipeline=$true)]
        [string]
        $DomainName,
        
        # Specify a selector name to use in the query.
        [Parameter()]
        [string[]]
        $Selector = @("selector1","selector2"),
        
        # Specify a DNS server to query.
        [Parameter()]
        [string] 
        $Server
    )
    process {
        foreach ($S in $Selector) {
            $params = @{
                Name = "$s._domainkey.$DomainName"
                ErrorAction = "SilentlyContinue"
            }
            if($Server) { 
                $params.Add("Server",$Server) 
            }
            Write-Verbose "Looking up $($Params.Name)" 
            # first get the target of the alias
            $dnsTarget = Resolve-DnsName @params -Type CNAME | Where-Object Type -eq CNAME
            if($dnsTarget){
                $params.Name = $dnsTarget.NameHost
                $dnsTxt = Resolve-DnsName @params -Type TXT | Where-Object Type -eq TXT  
                New-Object -TypeName psobject -Property ([ordered]@{
                    DomainName = "$DomainName`:$s"
                    Record = $dnsTxt.Strings
                })
            } else {
                Write-Warning "Could not find CName."
            }    
        }
    }    
}