- start the program 'amavisd', either as root (possibly with option
  -u user), or with su(1) as the user chosen above. It should
  start up, and (if root) change its GID/UID to the setting provided.
  It is wise to start it up for the first time with a 'debug' option:
    /usr/local/sbin/amavisd -u vscan debug
  or:
    /usr/local/sbin/amavisd debug
  When checking SpamAssassin operations, the following can be useful:
    /usr/local/sbin/amavisd debug-sa