(Delphi ActiveX) IMAP Download and Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

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
success: Integer;
imap: TChilkatImap;
fetchUids: Integer;
messageSet: TMessageSet;
email: TChilkatEmail;
cert: TChilkatCert;
i: Integer;
uid: WideString;

begin
success := 0;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

imap := TChilkatImap.Create(Self);

// Connect to an IMAP server.
// Use TLS
imap.Ssl := 1;
imap.Port := 993;
success := imap.Connect('imap.example.com');
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

success := imap.Login('myLogin','myPassword');
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

// Select an IMAP mailbox
success := imap.SelectMailbox('Inbox');
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

// We can choose to fetch UIDs or sequence numbers.
fetchUids := 1;

// Get the message IDs of all the emails in the mailbox
messageSet := TMessageSet.Create(Self);
success := imap.QueryMbx('ALL',fetchUids,messageSet.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(imap.LastErrorText);
    Exit;
  end;

email := TChilkatEmail.Create(Self);
cert := TChilkatCert.Create(Self);

i := 0;
while i < messageSet.Count do
  begin

    uid := messageSet.GetId(i);
    Memo1.Lines.Add('uid: ' + uid);

    success := imap.FetchEmail(0,uid,1,email.ControlInterface);
    if (success = 0) then
      begin
        Memo1.Lines.Add(imap.LastErrorText);
        Exit;
      end;

    // The security layers of signed and/or encrypted emails
    // are automatically "unwrapped" when loaded into
    // a Chilkat email object.
    // An application only needs to check to see if an email
    // was received signed or encrypted, and then examine
    // the success/failure.  For example:
    if (email.ReceivedSigned = 1) then
      begin

        Memo1.Lines.Add('This email was signed.');

        // Check to see if the signatures were verified.
        if (email.SignaturesValid = 1) then
          begin
            Memo1.Lines.Add('Digital signature(s) verified.');
            Memo1.Lines.Add('Signer: ' + email.SignedBy);

            // Get the certificate used for signing.
            success := email.LastSignerCert(0,cert.ControlInterface);

            if (success = 0) then
              begin
                Memo1.Lines.Add('Failed to get signing certificate object.');
              end
            else
              begin
                Memo1.Lines.Add('Signing cert: ' + cert.SubjectCN);
              end;

          end
        else
          begin
            Memo1.Lines.Add('Digital signature verification failed.');
          end;

      end;

    i := i + 1;
  end;

// Disconnect from the IMAP server.
success := imap.Disconnect();
end;