I ask not to abuse strongly, translated the translator.
Long searched at a forum and in Wiki as it to create but has come across only such variant How to create a /dev/null account or spam trap? - Zimbra :: Wiki.
In it there is a lack, it is necessary to adjust the filter at each user. More conveniently in the management console, in adjustment AS/AV will add instructions on the user which to accept all spam and possibility to send or not it to a box of the end user.