Sending an email using MAPI

There are lot of different methods to send mail using MAPI (Windows Simple Mail API)
If you do not want to rely on Outlook to send an email but you know that MAPI is installed, then you can also send mails with the following handy routine SendMailMAPI(). You need to add unit MAPI to your uses clause. Note that MAPI is not always installed with Windows.

unit uMAPIMail;

interface

uses MAPI;

function SendMailMAPI(const Subject, Body, FileName, SenderName, SenderEMail,
RecepientName, RecepientEMail: String) : Integer;

implementation

function SendMailMAPI(const Subject, Body, FileName, SenderName, SenderEMail,
RecepientName, RecepientEMail: String) : Integer;
var
message: TMapiMessage;
lpSender,
lpRecepient: TMapiRecipDesc;
FileAttach: TMapiFileDesc;
SM: TFNMapiSendMail;
MAPIModule: HModule;
begin
FillChar(message, SizeOf(message), 0);
with message do
begin
if (Subject<>'') then
begin
lpszSubject := PChar(Subject)
end;
if (Body<>'') then
begin
lpszNoteText := PChar(Body)
end;
if (SenderEMail<>'') then
begin
lpSender.ulRecipClass := MAPI_ORIG;
if (SenderName='') then
begin
lpSender.lpszName := PChar(SenderEMail)
end
else
begin
lpSender.lpszName := PChar(SenderName)
end;
lpSender.lpszAddress := PChar('SMTP:'+SenderEMail);
lpSender.ulReserved := 0;
lpSender.ulEIDSize := 0;
lpSender.lpEntryID := nil;
lpOriginator := @lpSender;
end;
if (RecepientEMail<>'') then
begin
lpRecepient.ulRecipClass := MAPI_TO;
if (RecepientName='') then
begin
lpRecepient.lpszName := PChar(RecepientEMail)
end
else
begin
lpRecepient.lpszName := PChar(RecepientName)
end;
lpRecepient.lpszAddress := PChar('SMTP:'+RecepientEMail);
lpRecepient.ulReserved := 0;
lpRecepient.ulEIDSize := 0;
lpRecepient.lpEntryID := nil;
nRecipCount := 1;
lpRecips := @lpRecepient;
end
else
begin
lpRecips := nil
end;
if (FileName='') then
begin
nFileCount := 0;
lpFiles := nil;
end
else
begin
FillChar(FileAttach, SizeOf(FileAttach), 0);
FileAttach.nPosition := Cardinal($FFFFFFFF);
FileAttach.lpszPathName := PChar(FileName);
nFileCount := 1;
lpFiles := @FileAttach;
end;
end;
MAPIModule := LoadLibrary(PChar(MAPIDLL));
if MAPIModule=0 then
begin
Result := -1
end else
begin
try
@SM := GetProcAddress(MAPIModule, 'MAPISendMail');
if @SM<>nil then
begin
Result := SM(0, Application.Handle, message, MAPI_DIALOG or MAPI_LOGON_UI,0);
end else
begin
Result := 1
end;

finally
FreeLibrary(MAPIModule);
end;
end
if Result<>0 then
begin
MessageDlg('Error sending mail ('+IntToStr(Result)+').', mtError, [mbOk], 0)
end;
end;

end.

Sending Mail using Thread

unit uSMTPMailer;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, 
  Dialogs, IdMessage, IdBaseComponent, IdComponent, IdTCPConnection,
  IdTCPClient, IdMessageClient, IdSMTP, StdCtrls;

type
  TSendMail = class(TThread)
  private
    FPortNumber: Integer;
    FSubject: String;
    FPassword: String;
    FServerName: String;
    FFromAddress: String;
    FBodyMessage: TStrings;
    FRecipientsList: TStrings;
    procedure SetBodyMessage(const Value: TStrings);
    procedure SetFromAddress(const Value: String);
    procedure SetPasword(const Value: String);
    procedure SetPortNumber(const Value: Integer);
    procedure SetRecipientsList(const Value: TStrings);
    procedure SetServerName(const Value: String);
    procedure SetSubject(const Value: String);
  public
    constructor Create(ASuspended: Boolean);
    property PortNumber: Integer read FPortNumber write SetPortNumber;
    property ServerName: String read FServerName write SetServerName;
    property Password: String read FPassword write SetPasword;
    property FromAddress: String read FFromAddress write SetFromAddress;
    property Recipients: TStrings  read FRecipientsList write SetRecipientsList;
    property Subject: String read FSubject write SetSubject;
    property Body: TStrings read FBodyMessage write SetBodyMessage;
    procedure SendEMail;
  protected
    procedure Execute;  override;
  end;

  function SendSMTPMail(APort: Integer;
                        ASMTPServer, APassword, AFromAddress: String;
                        AToAddresses, ABodyText: TStrings): Boolean;

implementation

{ TSendMail }
constructor TSendMail.Create(ASuspended: Boolean);
begin
  inherited Create(ASuspended);
  FreeOnTerminate := True;
  FBodyMessage := TStringList.Create;
  FRecipientsList := TStringList.Create;
end;

procedure TSendMail.Execute;
var
  FIdSMTP: TIdSMTP;
  FIdMessage: TIdMessage;
begin
  FIdSMTP := TIdSMTP.Create(nil);
  FIdMessage := TIdMessage.Create(nil);
  try
    FIdSMTP.Host := FServerName;
    FIdSMTP.Port := FPortNumber;
    FIdSMTP.Password:= FPassword;
    FIdMessage.From.Address := FFromAddress;
    FIdmessage.Recipients.Assign(FRecipientsList);
    FIdMessage.Subject := FSubject;
    FIdMessage.Body.Assign(FBodyMessage);
    try
      FIdSMTP.Connect;
      FIdSMTP.Send(FIdMessage);
    except end;
  finally
    if FIdSMTP.Connected then FIdSMTP.Disconnect;
    FreeAndNil(FIdMessage);
    FreeAndNil(FIdSMTP);
  end;
end;

procedure TSendMail.SendEMail;
begin
  Resume;
end;

procedure TSendMail.SetBodyMessage(const Value: TStrings);
begin
  FBodyMessage.Assign(Value);
end;

procedure TSendMail.SetFromAddress(const Value: String);
begin
  FFromAddress := Value;
end;

procedure TSendMail.SetPasword(const Value: String);
begin
  FPassword := Value;
end;

procedure TSendMail.SetPortNumber(const Value: Integer);
begin
  FPortNumber := Value;
end;

procedure TSendMail.SetRecipientsList(const Value: TStrings);
begin
  FRecipientsList.Assign(Value);
end;

procedure TSendMail.SetServerName(const Value: String);
begin
  FServerName := Value;
end;

procedure TSendMail.SetSubject(const Value: String);
begin
  FSubject := Value;
end;

function SendSMTPMail(APort: Integer; ASMTPServer, APassword,
  AFromAddress: String; AToAddresses, ABodyText: TStrings): Boolean;
begin
  try
    with TSendMail.Create(True) do
    begin
      PortNumber := APort;
      ServerName := ASMTPServer;
      Password   := APassword;
      FromAddress := AFromAddress;
      Recipients.Assign(AToAddresses);
      Body.Assign(ABodyText);
      SendEMail;
      {no need to free, its a self destructive thread}
    end;
    Result := True;
  except
    Result := False;
  end;
end;

end.