I'm using Horde Groupware Webmail Edition 4 on a Cyrus. Filtering emails is done with Sieve and I'm using Ingo as GUI. But now there's a new requirement. I'm looking for an answer to the question, if I can use the "addheader" (and perhaps "deleteheader" too) directive from Sieve (as described in http://www.ietf.org/rfc/rfc5293.txt) with Ingo? Regards