Due huge changes in the source an upgrade from 3.4.x to 3.6.x has to be done 
manually, please read these files:

/usr/share/doc/dspam-3.9.0/RELEASE.NOTES
/usr/share/doc/dspam-3.9.0/UPGRADING

The previous 3.4.x packages was specially handcrafted so that you could use each
driver and even toggle between them, or use them simultaneousely. This is not
nessesary anymore and that magic has therefore been removed.

The Berkley-DB backend driver has been removed as it is prone to give errors due 
lack of thread safety as outlined in the dspam documentation.

The amavis-new tailored package has been removed, it may reappear later on.

You will have to define a proper cron command to use for daily cleanups. Look
in the /etc/sysconfig/dspam file for some examples.

For example when executing dspam with the mysql driver it is possible it will
complain that it cannot find a /var/lib/dspam/mysql.data file. This
is for backward compatibility. Do not use this file, edit the /etc/dspam.conf
file instead.

The dspam-cgi web interface is password protected and only accessable from 127.0.0.1,
login as dspamadmin (l/p=dspamadmin) and change this ASAP in the 
/usr/share/dspam/cgi-bin/.htpasswd file. Preferably you should use some other
authentication mechanish.