I tried this configuration: client = yes debug = debug cert =/Users/etc/stunnel/stunnel.pem [imaps] accept = localhost:143 delay = yes connect = remote:993 and it worked! But if I change "accept = localhost:143" to "accept = localhost:993" it does not work. I need a imaps proxy. Logs does not say anything interesting (SSL accepted: new session negotiated) Thank you all, Miguel