Starting from this code:

int AsyncMail::SendMail(const WCHAR *address)
{
::CoInitialize(NULL);
IMailPtr oSmtp = NULL;
oSmtp.CreateInstance("EASendMailObj.Mail");
oSmtp->LicenseCode = _T("TryIt");

// Set your sender email address
oSmtp->FromAddr = _T("xxxxx");

// Add recipient email address
oSmtp->AddRecipientEx(address, 0);

// Set email subject
oSmtp->Subject = _T("email from Visual C++ project in asynchronous mode ");

// Set email body
oSmtp->BodyText = _T("this is a test email sent from Visual C++ asynchronously");

// Your SMTP server address
oSmtp->ServerAddr = _T("smtp.libero.it");

// User and password for ESMTP authentication, if your server doesn't
// require User authentication, please remove the following codes.
oSmtp->UserName = _T(xxxxx");
oSmtp->Password = _T("yyyyy");


oSmtp->FromAddr = _T("xxxxxxx");

// If your SMTP server requires SSL connection, please add this line
oSmtp->SSL_init();

_tprintf(_T("Start to send email ...\r\n"));

// Attach event connection pointer
CMailEvents oEvents;
oEvents.DispEventAdvise(oSmtp.GetInterfacePtr());
oEvents.m_bFinished = FALSE;
oEvents.m_bError = FALSE;
// Set asynchronous mode
oSmtp->Asynchronous = 1;
oSmtp->SendMail();

// Waiting for email sending ...
while (!oEvents.m_bFinished)
{
MSG msg;
while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
if (msg.message == WM_QUIT)
return 0;
TranslateMessage(&msg);
DispatchMessage(&msg);
}

// You can do other thing here
::Sleep(10);
}
// Detach event connection pointer
oEvents.DispEventUnadvise(oSmtp.GetInterfacePtr());
if (!oEvents.m_bError)
{
_tprintf(_T("email was sent successfully!\r\n"));
}
else
{
_tprintf(_T("failed to send email with the following error: %s\r\n"),
(const TCHAR*)oEvents.m_lastError);
}
if (oSmtp != NULL)
oSmtp.Release();
return 0;
}


So, basically this code works but I'd like to send anonymous email or an email with a fake fantasy address.
Suggestions?

In EASendMail, you can set any email address in FromAddr property:

oSmtp->FromAddr = _T("xxxxxxx");

However, most email servers will check if the from address is same as the authenticated user. And I don't suggest that you use faked or anonymous email address, most email servers will reject your message or mark your email as spam.