(Delphi ActiveX) Transition from MailMan.MxLookup to Dns.Query

Provides instructions for replacing deprecated MxLookup method calls with the Chilkat Dns class.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
mailman: TChilkatMailMan;
emailAddr: WideString;
domain: WideString;
dns: TChilkatDns;
json: TChilkatJsonObject;
success: Integer;
i: Integer;
count_i: Integer;

begin
mailman := TChilkatMailMan.Create(Self);

// ...
// ...

emailAddr := 'joe@example.com';

// ------------------------------------------------------------------------
// The MxLookup method is deprecated:

domain := mailman.MxLookup(emailAddr);
if (mailman.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(mailman.LastErrorText);
    Exit;
  end;

// ------------------------------------------------------------------------
// Do the equivalent using the Chilkat DNS class

dns := TChilkatDns.Create(Self);

json := TChilkatJsonObject.Create(Self);

// This gets all MX domains for an email address.  (Typically one domain.)
// The preferred domain will be at index 0 (see below).
success := dns.Query('MX',emailAddr,json.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(dns.LastErrorText);
    Exit;
  end;

i := 0;
count_i := json.SizeOfArray('answer.mx');
while i < count_i do
  begin
    json.I := i;
    domain := json.StringOf('answer.mx[i].domain');
    Memo1.Lines.Add(domain);
    i := i + 1;
  end;
end;