For many years, on Red Hat distros, the common respository for SSL certificates has been the /usr/share/ssl/certs directory. You'll find the SSL certifcate for cyrus-imapd, dovect, exim, and OpenLDAP in that directory by default. Also, the bundle of trusted CA certicates is also located in that directory.
This is changing for Fedora Core v4 and the future Red Hat Enterprise Linux v5.
This initially caused some breakage in applications that hard coded the path to the CA bundle. One example was Postfix.
Applications shouldn't be hard coding the path, and instead should make use of the OpenSSL API functions X509_get_default_cert_file() or SSL_CTX_set_default_verify_paths().
Additionally, any HOWTO or documentation out there should be updated to reference the new path. We have already updated the development tree of our Linux courseware.