With previous versions I could use an own form which passed on the logon credentials to the smartermail interface and so end up in the inbox (see code below). Is this feature not available anymore?

<form name="mailform1" action="LinkToSmarterMail" method="post" target="_blank">
<input type="hidden" name="shortcutLink" value="autologin" id="shortcutLink">
<input type="hidden" name="email" id="email" value="EmailFromForm">
<input type="hidden" name="password" id="password" value="PasswordFromForm">
</form>