[Moved from here
Maybe someone can give me a hand here: Due to the fact that the sieverules-plugin of roundcube allows more complex filtering solutions than ISPConfig we found the require-line which is written by ispconfig insufficient:
require ["fileinto", "regex", "vacation"];
Because some of our users are utilizing the copy-function for instance the require line would read:
As far as I'm concerned the require line is written statically to the dovecot.sieve-file. In which file is this directive defined so we can simply add more sieve-filter-features?