Delphi ActiveX

Transition from MailMan.MxLookup to Dns.Query

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

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
success: Integer;
mailman: TChilkatMailMan;
emailAddr: WideString;
domain: WideString;
dns: TChilkatDns;
json: TChilkatJsonObject;
i: Integer;
count_i: Integer;

begin
success := 0;

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;