Erro Ao Montar Mensagem De Email, Outlook express

Ola..pessoal.

Estou com um problema numa maquina do usuario

neste maquina eu fiz uma rotina pra montar email usando o Outlook express...

Então agora ao clickar no botão da a seguinte mensagem de erro:

Error While Trying to send email

Eu uso esta função pra mandar o email:

Uses

Mapi

function SendEMail(Handle: THandle; Mail: TStrings):

Cardinal;

type

TAttachAccessArray = array [0..0] of TMapiFileDesc;

PAttachAccessArray = ^TAttachAccessArray;

var

MapiMessage: TMapiMessage;

Receip: TMapiRecipDesc;

Attachments: PAttachAccessArray;

AttachCount: Integer;

i1: integer;

FileName: string;

dwRet: Cardinal;

MAPI_Session: Cardinal;

WndList: Pointer;

begin

dwRet := MapiLogon(Handle,

PChar(''),

PChar(''),

MAPI_LOGON_UI or MAPI_NEW_SESSION,

0, @MAPI_Session);

if (dwRet <> SUCCESS_SUCCESS) then

begin

MessageBox(Handle,

PChar('Error while trying to send email'),

PChar('Error'),

MB_ICONERROR or MB_OK);

end

else

begin

FillChar(MapiMessage, SizeOf(MapiMessage), #0);

Attachments := nil;

FillChar(Receip, SizeOf(Receip), #0);

if Mail.Values['to'] <> '' then

begin

Receip.ulReserved := 0;

Receip.ulRecipClass := MAPI_TO;

Receip.lpszName :=

StrNew(PChar(Mail.Values['to']));

Receip.lpszAddress := StrNew(PChar('SMTP:' +

Mail.Values['to']));

Receip.ulEIDSize := 0;

MapiMessage.nRecipCount := 1;

MapiMessage.lpRecips := @Receip;

end;

AttachCount := 0;

for i1 := 0 to MaxInt do

begin

if Mail.Values['attachment' + IntToStr(i1)] = ''

then

break;

Inc(AttachCount);

end;

if AttachCount > 0 then

begin

GetMem(Attachments, SizeOf(TMapiFileDesc) *

AttachCount);

for i1 := 0 to AttachCount - 1 do

begin

FileName := Mail.Values['attachment' +

IntToStr(i1)];

Attachments[i1].ulReserved := 0;

Attachments[i1].flFlags := 0;

Attachments[i1].nPosition := ULONG($FFFFFFFF);

Attachments[i1].lpszPathName :=

StrNew(PChar(FileName));

Attachments[i1].lpszFileName :=

StrNew(PChar(ExtractFileName(FileName)));

Attachments[i1].lpFileType := nil;

end;

MapiMessage.nFileCount := AttachCount;

MapiMessage.lpFiles := @Attachments^;

end;

if Mail.Values['subject'] <> '' then

MapiMessage.lpszSubject :=

StrNew(PChar(Mail.Values['subject']));

if Mail.Values['body'] <> '' then

MapiMessage.lpszNoteText :=

StrNew(PChar(Mail.Values['body']));

WndList := DisableTaskWindows(0);

try

Result := MapiSendMail(MAPI_Session, Handle,

MapiMessage, MAPI_DIALOG, 0);

finally

EnableTaskWindows( WndList );

end;

for i1 := 0 to AttachCount - 1 do

begin

StrDispose(Attachments[i1].lpszPathName);

StrDispose(Attachments[i1].lpszFileName);

end;

if Assigned(MapiMessage.lpszSubject) then

StrDispose(MapiMessage.lpszSubject);

if Assigned(MapiMessage.lpszNoteText) then

StrDispose(MapiMessage.lpszNoteText);

if Assigned(Receip.lpszAddress) then

StrDispose(Receip.lpszAddress);

if Assigned(Receip.lpszName) then

StrDispose(Receip.lpszName);

MapiLogOff(MAPI_Session, Handle, 0, 0);

end;

end;

exemplo de envio no botão:

procedure TForm1.BitBtn5Click(Sender: TObject);
var
mail: TStringList;
begin
mail := TStringList.Create;
try
mail.values['to'] := 'Email@test.xyz'; ///AQUI VAI O EMAIL DO DESTINATARIO///
mail.values['subject'] := 'Hello'; ///AQUI O ASSUNTO///
mail.values['body'] := 'blah'; ///AQUI O TEXTO NO CORPO DO EMAIL///
mail.values['attachment0'] := 'C:\Test.txt'; ////AQUI O ENDEREÇO ONDE ENCONTRAM OS ARQUIVOS//
mail.values['attachment1']:='C:\Test2.txt'; ///IDEM - NO ATTACHMENT1 TEM QUE COLOCAR A SEQUNCIA DO EMAIL A QUAL DESEJA ENVIAR EXEMPLO: ATTACHMENT1
sendEMail(Application.Handle, mail);
finally

mail.Free;
end;
end;

Alguém teria alguma ideia pra resolver este problema??

só acontece em uma maquina...as outras usam o mesmo programa e não da erro.

Agradecido..