I have some problem with dspam in zimbra 8

(Release 8.0.0.GA.5434.UBUNTU12.64 UBUNTU12_64 FOSS edition.)

Oct 30 12:22:47 mail dspam[22423]: Unable to determine the destination user
Oct 30 12:22:47 mail amavis[21202]: (21202-01) (!)auto-learning with spam scanner DSPAM failed: DSPAM: error running program /opt/zimbra/dspam/bin/dspam: exit 1
Oct 30 12:22:47 mail amavis[21202]: (21202-01) (!)Auto-learn failed: DSPAM failed: DSPAM: error running program /opt/zimbra/dspam/bin/dspam: exit 1 at (eval 113) line 207.
Oct 30 12:22:47 mail dspam[22423]: DSPAM agent misconfigured: aborting