If you're using SSL, then you can define the path to your certificate and key as in:
Code:
ssl_cert = </etc/ssl-certs/server.crt
ssl_key = </etc/ssl-certs/server.key
or you can disable ssl if you're not using it by adding/changing the following in your dovecot configuration file:
in dovecot2 the configuration is split into multiple files within dovecot/conf.d directory. so this should be set in conf.d/10-ssl.conf
dovecot2 wiki page is at
http://wiki2.dovecot.org/FrontPage