Most the guides out there for setting up spamassassin seem to convey that simply installing dcc and the likes makes them work. I ran tcpdump on port 6277 though and didn’t see any dcc traffic.

1) I found that DCC in commented out by default under /etc/spamassassin/v310.pre
2) I added the following to /etc/spamassassin/local.cf:

use_dcc 1
dcc_path /usr/bin/dccproc
dcc_add_header 1
dcc_dccifd_path /usr/sbin/dccifd

Note thatI think dcc_add_header is legacy and doesn’t work, and that the dcc_ifd path throws an error in the next debug section, so is likely not needed.

Then I found when running a test:

Step4: Test DCC is working via Spamassassin

First you can download a common spam message that will trigger DCC detection at:

# wget ‘http://kb.atmail.com/attach/spam-mail.txt’

Next, test a message via Spamassassin in debug mode for the results

# spamassassin -t -D < spam-mail.txt

I saw DCC traffic, but not when amavis was running. Recalling how I had to add clamav to the amavis user, as everything runs non-root, so:

3) I added the dcc user to the amavis group and restarted amavis for the sake of it, and I’m seeing dcc traffic now on port 6277.