Sample code for 30+ languages & platforms
Delphi DLL

POP3 Read S/MIME Encrypted Email

Read S/MIME encrypted email.

Chilkat Delphi DLL Downloads

Delphi DLL
uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, MailMan, EmailBundle, Email;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
mailman: HCkMailMan;
bundle: HCkEmailBundle;
keepOnServer: Boolean;
headersOnly: Boolean;
numBodyLines: Integer;
email: HCkEmail;
i: Integer;

begin
success := False;

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

// The mailman object is used for receiving (POP3) 
// and sending (SMTP) email.
mailman := CkMailMan_Create();

// Set the POP3 server's hostname
CkMailMan_putMailHost(mailman,'pop.example.com');

// Set the POP3 login/password.
CkMailMan_putPopUsername(mailman,'myLogin');
CkMailMan_putPopPassword(mailman,'myPassword');

// If running on Microsoft Windows, the Chilkat mailman
// will automatically search the registry-based certificate stores
// for matching certificates and private keys required for
// decryption.  However, on Linux, MAX OS X, and other
// operating systems, no such thing exists.  Therefore, you'll 
// need to specify one or more PFX (.p12 / .pfx) files as
// sources for locating the certs required for decyrption.
success := CkMailMan_AddPfxSourceFile(mailman,'/pfxFiles/certs_and_keys_1.pfx','pfxPassword1');
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

success := CkMailMan_AddPfxSourceFile(mailman,'/pfxFiles/certs_and_keys_2.pfx','pfxPassword2');
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// ...
// Note: On MS Windows, it is not required to provide PFX sources
// if the needed certs and private keys are already installed
// on the system (in the registry-based certificate stores).

// Copy the all email from the user's POP3 mailbox 
// into a bundle object.  The email remains on the server.
bundle := CkEmailBundle_Create();
keepOnServer := True;
headersOnly := False;
// Irrelevent because we are NOT downloading headers-only
numBodyLines := 0;
success := CkMailMan_FetchAll(mailman,keepOnServer,headersOnly,numBodyLines,bundle);
if (success = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// S/MIME security envelopes are automatically "unwrapped" 
// when a message is retrieved from the server. Signed emails are automatically verified, and 
// encrypted emails are automatically decrypted, restoring the email to the original state before 
// signing and/or encrypting. Information about the signing and encrypting certificates can be 
// retrieved from the Email object (methods: GetSignedByCert, GetEncryptedByCert; 
// properties: SignedBy, EncryptedBy, SignaturesValid, Decrypted, ReceivedSigned, 
// ReceivedEncrypted).

// Loop over the bundle
email := CkEmail_Create();
i := 0;
while i < CkEmailBundle_getMessageCount(bundle) do
  begin

    CkEmailBundle_EmailAt(bundle,i,email);

    Memo1.Lines.Add(CkEmail__from(email));
    Memo1.Lines.Add(CkEmail__subject(email));

    // At this point, if the email was signed and/or encrypted, it is already "unwrapped", i.e.
    // the email is already decrypted and in a state as if it were never signed or encrypted.
    // You may check to see if the email was received encrypted or signed, and if so,
    // whether it was successfully unwrapped and who signed or encrypted it:
    if (CkEmail_getReceivedEncrypted(email) = True) then
      begin

        Memo1.Lines.Add('This email was encrypted when received.');
        if (CkEmail_getDecrypted(email) = True) then
          begin
            Memo1.Lines.Add('This email was successfully decrypted.  It was encrypted by:');
            Memo1.Lines.Add(CkEmail__encryptedBy(email));
          end
        else
          begin
            Memo1.Lines.Add('This email was not decrypted.');
          end;
      end;
    if (CkEmail_getReceivedSigned(email) = True) then
      begin

        Memo1.Lines.Add('This email was signed when received.');
        if (CkEmail_getSignaturesValid(email) = True) then
          begin
            Memo1.Lines.Add('The signature was verified.  It was signed by:');
            Memo1.Lines.Add(CkEmail__signedBy(email));
          end
        else
          begin
            Memo1.Lines.Add('The signature verification failed.');
          end;
      end;

    // The email's body, HTML body, attachments, etc.
    // are decrypted and available just like any non-encrypted email.

    Memo1.Lines.Add('--');

    i := i + 1;
  end;

CkMailMan_Dispose(mailman);
CkEmailBundle_Dispose(bundle);
CkEmail_Dispose(email);

end;