diff --git a/setup/spamassassin.sh b/setup/spamassassin.sh
index 35cab605..27576766 100755
--- a/setup/spamassassin.sh
+++ b/setup/spamassassin.sh
@@ -16,8 +16,11 @@ source setup/functions.sh # load our functions
 # ----------------------------------------
 
 # Install packages.
+# libmail-dkim-perl is needed to make the spamassassin DKIM module work.
+# For more information see Debian Bug #689414:
+# https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=689414
 echo "Installing SpamAssassin..."
-apt_install spampd razor pyzor dovecot-antispam
+apt_install spampd razor pyzor dovecot-antispam libmail-dkim-perl
 
 # Allow spamassassin to download new rules.
 tools/editconf.py /etc/default/spamassassin \
@@ -42,9 +45,11 @@ echo "public.pyzor.org:24441" > /etc/spamassassin/pyzor/servers
 #   want to lose track of it. (We've configured Dovecot to listen on this port elsewhere.)
 # * Increase the maximum message size of scanned messages from the default of 64KB to 500KB, which
 #   is Spamassassin (spamc)'s own default. Specified in KBytes.
+# * Disable localmode so Pyzor, DKIM and DNS checks can be used.
 tools/editconf.py /etc/default/spampd \
 	DESTPORT=10026 \
-	ADDOPTS="\"--maxsize=500\""
+	ADDOPTS="\"--maxsize=500\"" \
+	LOCALONLY=0
 
 # Spamassassin normally wraps spam as an attachment inside a fresh
 # email with a report about the message. This also protects the user