DCC is an anti-spam content filter and I have very good experience with it. DCC stands for Distributed Checksum Clearinghouses. I use it together with SpamAssassin to tag mails as spam on my mail server. I have been using DCC for several years and my experience is very good.

Unfortunately is DCC not included with Ubuntu (or Debian). Due to this I maintain a set of DCC packages in my PPA. Below you will find a guide to download, install and configure DCC on your Ubuntu box. It is assumed that you already have SpamAssassin configured.

Download and install

To download and install DCC follow below steps. As DCC is stored in my personal PPA you need to activate this PPA and you can then install it through apt, Ubuntu Software Center etc.

  1. Activate my PPA. You can find more details at or run the command apt-add-repository ppa:jonasped/ppa in a terminal.
  2. Update your package index with apt-get update from a terminal or use your fevourite GUI tool.
  3. Install DCC with the command apt-get install dcc-client or use your favourite GUI tool


Configuration of DCC is really simple. All you need to do is to enable to the plugin in SpamAssassin.

  1. Edit /etc/spamassassin/v310.pre and enable the plugin Mail::SpamAssassin::Plugin::DCC.
That is it. You have now installed DCC and SpamAssassin will use DCC when tagging mail as spam.