Regarding MDB2_Driver_mysql, I point towards (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=544694). If you want to use mysql and not default sqlite, use debian package roundcube-mysql and it will install the dependencies for you.
As for users, roundcube uses imap and thus do not create new users.
Anyway, GL, and if you want to have some fun, try out PostgreSQL.
As for users, roundcube uses imap and thus do not create new users.
Anyway, GL, and if you want to have some fun, try out PostgreSQL.