This documentation is for Dovecot v1.x, see wiki2 for v2.x documentation.

SSL

You can have both the certificate and the key in one file, but you must still mention the file for both conf settings, like so:

ssl_cert_file = /usr/local/etc/ssl/private/dovecot.pem
ssl_key_file  = /usr/local/etc/ssl/private/dovecot.pem

Because the secret key is now part of the certificate file, it should not be world-read/writeable (preferred permissions are 0400, owner root:root).