Replaced blacklisting approach with a whitelisting on, thus preventing access due to responses from authlib not containing the word 'FAIL', e.g. empty ones (see http://www.courier-mta.org/authlib/README_authlib.html#authpipeproto)
Replaced blacklisting approach with a whitelisting on, thus preventing access due to responses from authlib not containing the word 'FAIL', e.g. empty ones (see http://www.courier-mta.org/authlib/README_authlib.html#authpipeproto)