On Oct 3, 2013, at 04.46, Dieter Klünter <dieter@dkluenter.de> wrote: > > You are connnecting to port 389, but s_client is not able to initiate a > LDAP startTLS session (only SMTP and IMAP), so you have to connect > ldaps and port 636. s_client does support starttls for other protocols aside from smtp and imap [pop3, ftp, xmpp]. just not ldap. -ben