Parse winmail.dat (TNEF/MAPI) in Delphi

In previous section, I introduced how to verify digital signature and decrypt email. In this section, I will introduce how to parse winmail.dat (TNEF stream) in Delphi.

Introduction

When an Outlook user composes and sends a message using either Rich Text Format or HTML Format, Outlook automagically generates a file, winmail.dat, and attaches it to the end of the email. The winmail.dat contains the rich text body and original attachments. To parse winmail.dat (TNEF stream) file, we should use ParseTNEF method.

Note

Remarks: All of examples in this section are based on first section: A simple Delphi project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference to your project.

[Delphi Example - Parse winmail.dat (TNEF stream)]

The following example codes demonstrate how to parse MAPI winmail.dat.

Note

To get the full sample projects, please refer to Samples section.

unit Unit1;

interface

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls, EAGetMailObjLib_TLB; // Add EAGetMail unit

type
    TForm1 = class(TForm)
        Button1: TButton;
        procedure Button1Click(Sender: TObject);
        procedure ParseEmail( fileName: WideString );
    private
        { Private declarations }
    public
        { Public declarations }
    end;

const
    MailServerPop3 = 0;
    MailServerImap4 = 1;

    CRYPT_MACHINE_KEYSET = 32;
    CRYPT_USER_KEYSET = 4096;
    CERT_SYSTEM_STORE_CURRENT_USER = 65536;
    CERT_SYSTEM_STORE_LOCAL_MACHINE = 131072;

var
    Form1: TForm1;

implementation

{$R *.dfm}
procedure TForm1.ParseEmail( fileName: WideString );
var
    oMail: TMail;
    i, UBound, x, XBound: integer;
    addrs, atts, tatts: OleVariant;
    addr: IMailAddress;
    att, tatt: IAttachment;
    oCert: TCertificate;
    oSignerCert: ICertificate;
begin
    oMail := TMail.Create(Application);
    oMail.LicenseCode := 'TryIt';
    oMail.LoadFile(fileName, false);
    ShowMessage(oMail.Headers.GetValueOfKey('Content-Type'));
    if oMail.IsEncrypted then
        try
            // this email is encrypted, decrypt it by default user certificate
            oMail.ConnectTo(oMail.Decrypt(nil));
            // You can also use specified certificate like this
            // oCert := TCertificate.Create(Application);
            // oCert.LoadFromFile( 'c:\test.pfx', 'pfxpassword', CRYPT_USER_KEYSET );
            // oMail.Load(oMail.Decrypt(oCert.DefaultInterface).Content);
        except
            on ep: Exception do
        begin
            ShowMessage('Decrypt Error: ' + ep.Message );
        end;
    end;

    if oMail.IsSigned then
        try
            // this email is digital signed, verify signature
            oSignerCert := oMail.VerifySignature();
            ShowMessage( 'This email contains a valid digital signature.' );
            // You can add the certificate to your certificate storage like this
            // oSignerCert.AddToStore(CERT_SYSTEM_STORE_CURRENT_USER,
            //    'addressbook');
            //  Then you can use send the encrypted email back to this sender.
        except
            on ep: Exception do
        begin
            ShowMessage('Verify signature Error: ' + ep.Message );
        end;
    end;


    // Parse email sender
    ShowMessage( 'From: ' + oMail.From.Address );

    // Parse email to recipients
    addrs := oMail.ToAddr;
    UBound := VarArrayHighBound( addrs, 1 );
    for i := 0 to UBound do
    begin
        addr := IDispatch(VarArrayGet(addrs, i)) as IMailAddress;
        ShowMessage( 'To: ' + addr.Address );
    end;

    // Parse email cc recipients
    addrs := oMail.Cc;
    UBound := VarArrayHighBound( addrs, 1 );
    for i := 0 to UBound do
    begin
        addr := IDispatch(VarArrayGet(addrs, i)) as IMailAddress;
        ShowMessage( 'Cc: ' + addr.Address );
    end;

    // Parse email subject
    ShowMessage( 'Subject: ' + oMail.Subject );

    // Parse email text body
    ShowMessage( 'Text body: ' + oMail.TextBody );

    // Parse email HTML body
    ShowMessage( 'HTML body: ' + oMail.HtmlBody );

    // Parse attachment
    atts := oMail.Attachments;
    UBound := VarArrayHighBound( atts, 1 );
    for i := 0 to UBound do
    begin
        att := IDispatch(VarArrayGet(atts,i)) as IAttachment;
        ShowMessage( att.Name );

        if LowerCase(att.Name) = 'winmail.dat' then
        begin
        // this is outlook rtf (TNEF) attachment, decode it here
        tatts := oMail.ParseTNEF(att.Content, true );
        XBound := VarArrayHighBound(tatts, 1 );
        for x:= 0 to XBound do
        begin
            tatt := IDispatch(VarArrayGet(tatts,x)) as IAttachment;
            ShowMessage( 'winmail.dat' + tatt.Name );
        end;
        end
    end;


end;

procedure TForm1.Button1Click(Sender: TObject);
var
    oTools: TTools;
    files: OleVariant;
    fileName: WideString;
    i, UBound: integer;
    mailFolder: WideString;
begin
try
    oTools := TTools.Create(Application);

    // Create a folder named "inbox" under
    // current directory to store the email files
    mailFolder := GetCurrentDir() + '\inbox';
    oTools.CreateFolder(mailFolder);

    // Get all *.eml files in specified folder and parse it one by one
    files := oTools.GetFiles(mailFolder + '\*.eml');
    UBound := VarArrayHighBound( files, 1 );
    for i := 0 to UBound do
    begin
        fileName := VarArrayGet(files, i);
        ParseEmail(fileName);
    end;

except
    on ep:Exception do
    ShowMessage( 'Error: ' + ep.Message );
end;

end;

end.

Parse TNEF (winmail.dat) by DecodeTNEF method

In EAGetMail 4.5, a new method named DecodeTNEF is introduced. It is easier to parse TNEF attachment. Please have a look at the following example codes:

unit Unit1;

interface

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls, EAGetMailObjLib_TLB; // Add EAGetMail unit

type
    TForm1 = class(TForm)
        Button1: TButton;
        procedure Button1Click(Sender: TObject);
        procedure ParseEmail( fileName: WideString );
    private
        { Private declarations }
    public
        { Public declarations }
    end;

const
    MailServerPop3 = 0;
    MailServerImap4 = 1;

    CRYPT_MACHINE_KEYSET = 32;
    CRYPT_USER_KEYSET = 4096;
    CERT_SYSTEM_STORE_CURRENT_USER = 65536;
    CERT_SYSTEM_STORE_LOCAL_MACHINE = 131072;

var
    Form1: TForm1;

implementation

{$R *.dfm}
procedure TForm1.ParseEmail( fileName: WideString );
var
    oMail: TMail;
    i, UBound, x, XBound: integer;
    addrs, atts, tatts: OleVariant;
    addr: IMailAddress;
    att, tatt: IAttachment;
    oCert: TCertificate;
    oSignerCert: ICertificate;
begin
    oMail := TMail.Create(Application);
    oMail.LicenseCode := 'TryIt';
    oMail.LoadFile(fileName, false);
    ShowMessage(oMail.Headers.GetValueOfKey('Content-Type'));
    if oMail.IsEncrypted then
    try
        // this email is encrypted, decrypt it by default user certificate
        oMail.ConnectTo(oMail.Decrypt(nil));
        // You can also use specified certificate like this
        // oCert := TCertificate.Create(Application);
        // oCert.LoadFromFile( 'c:\test.pfx', 'pfxpassword', CRYPT_USER_KEYSET );
        // oMail.Load(oMail.Decrypt(oCert.DefaultInterface).Content);
    except
        on ep: Exception do
        begin
            ShowMessage('Decrypt Error: ' + ep.Message );
        end;
    end;

    if oMail.IsSigned then
    try
        // this email is digital signed, verify signature
        oSignerCert := oMail.VerifySignature();
        ShowMessage( 'This email contains a valid digital signature.' );
        // You can add the certificate to your certificate storage like this
        // oSignerCert.AddToStore(CERT_SYSTEM_STORE_CURRENT_USER,
        //    'addressbook');
        //  Then you can use send the encrypted email back to this sender.
    except
        on ep: Exception do
        begin
            ShowMessage('Verify signature Error: ' + ep.Message );
        end;
    end;


    // Decode winmail.dat (TNEF) automatically'
    oMail.DecodeTNEF();

    // Parse email sender
    ShowMessage( 'From: ' + oMail.From.Address );

    // Parse email to recipients
    addrs := oMail.ToAddr;
    UBound := VarArrayHighBound( addrs, 1 );
    for i := 0 to UBound do
    begin
        addr := IDispatch(VarArrayGet(addrs, i)) as IMailAddress;
        ShowMessage( 'To: ' + addr.Address );
    end;

    // Parse email cc recipients
    addrs := oMail.Cc;
    UBound := VarArrayHighBound( addrs, 1 );
    for i := 0 to UBound do
    begin
        addr := IDispatch(VarArrayGet(addrs, i)) as IMailAddress;
        ShowMessage( 'Cc: ' + addr.Address );
    end;

    // Parse email subject
    ShowMessage( 'Subject: ' + oMail.Subject );

    // Parse email text body
    ShowMessage( 'Text body: ' + oMail.TextBody );

    // Parse email HTML body
    ShowMessage( 'HTML body: ' + oMail.HtmlBody );


    // Parse attachment
    atts := oMail.Attachments;
    UBound := VarArrayHighBound( atts, 1 );
    for i := 0 to UBound do
    begin
        att := IDispatch(VarArrayGet(atts,i)) as IAttachment;
        ShowMessage( att.Name );
    end;


end;

procedure TForm1.Button1Click(Sender: TObject);
var
    oTools: TTools;
    files: OleVariant;
    fileName: WideString;
    i, UBound: integer;
    mailFolder: WideString;
begin
    try
        oTools := TTools.Create(Application);

        // Create a folder named "inbox" under
        // current directory to store the email files
        mailFolder := GetCurrentDir() + '\inbox';
        oTools.CreateFolder(mailFolder);

        // Get all *.eml files in specified folder and parse it one by one
        files := oTools.GetFiles(mailFolder + '\*.eml');
        UBound := VarArrayHighBound( files, 1 );
        for i := 0 to UBound do
        begin
            fileName := VarArrayGet(files, i);
            ParseEmail(fileName);
        end;

    except
        on ep:Exception do
        ShowMessage( 'Error: ' + ep.Message );
    end;

end;

end.

Next Section

At next section I will introduce how to convert email to HTML page and display it in Web browser.

Appendix

Comments

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