optional_depends pcre \ "" "" \ "for PCRE tables support" && optional_depends db \ "" "" \ "for hash and btree files support" && optional_depends sqlite \ "" "" \ "for SQLite support" && optional_depends MYSQL \ "" "" \ "for MySQL support" && optional_depends postgresql \ "" "" \ "for PostgreSQL support" && optional_depends openldap \ "" "" \ "for LDAP support" && optional_depends linux-pam \ "" "" \ "for PAM support" && optional_depends SSL \ "" "" \ "for SSL/TLS support" && optional_depends dovecot \ "" "" \ "for SASL authentication via Dovecot" && optional_depends cyrus-sasl \ "" "" \ "for SASL authentication via the Cyrus libraries"