=head1 SYNOPSIS
B<openssl> B<s_client>
-[B<-connect> host:port>]
+[B<-connect host:port>]
[B<-verify depth>]
[B<-cert filename>]
[B<-key filename>]
[B<-no_tls1>]
[B<-bugs>]
[B<-cipher cipherlist>]
+[B<-starttls protocol>]
[B<-engine id>]
[B<-rand file(s)>]
supported cipher in the list sent by the client. See the B<ciphers>
command for more information.
+=item B<-starttls protocol>
+
+send the protocol-specific message(s) to switch to TLS for communication.
+B<protocol> is a keyword for the intended protocol. Currently, the only
+supported keywords are "smtp" and "pop3".
+
=item B<-engine id>
specifying an engine (by it's unique B<id> string) will cause B<s_client>
If the handshake fails then there are several possible causes, if it is
nothing obvious like no client certificate then the B<-bugs>, B<-ssl2>,
-B<-ssl3>, B<-tls1>, B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1> can be tried
+B<-ssl3>, B<-tls1>, B<-no_ssl2>, B<-no_ssl3>, B<-no_tls1> options can be tried
in case it is a buggy server. In particular you should play with these
options B<before> submitting a bug report to an OpenSSL mailing list.
requests a certificate. By using B<s_client> the CA list can be viewed
and checked. However some servers only request client authentication
after a specific URL is requested. To obtain the list in this case it
-is necessary to use the B<-prexit> command and send an HTTP request
+is necessary to use the B<-prexit> option and send an HTTP request
for an appropriate page.
If a certificate is specified on the command line using the B<-cert>