Log Message:
Update to 4.0.0. The changelog is unwieldy; highlights:

* Several options have changed names, behaviors, defaults, and/or
  possible settings, all of which are explained in the upgrade
  instructions.

* Many new options have been added:
  config-dir
  config-dir-search
  dns-blacklist-file
  dns-level
  dns-max-retries-total
  dns-max-retries-primary
  dns-server-ip
  dns-server-ip-primary
  dns-timeout-secs
  dns-whitelist-file
  filter-level
  graylist-exception-ip-entry
  graylist-exception-rdns-entry
  graylist-level
  ip-blacklist-entry
  ip-in-rdns-keyword-blacklist-entry
  ip-in-rdns-keyword-whitelist-entry
  ip-in-rdns-keyword-whitelist-file
  ip-whitelist-entry
  local-domain-entry
  rdns-blacklist-entry
  rdns-whitelist-entry
  recipient-blacklist-entry
  recipient-whitelist-entry
  rejection-text-access-denied
  rejection-text-dns-blacklist
  rejection-text-earlytalker
  rejection-text-empty-rdns
  rejection-text-graylist
  rejection-text-ip-blacklist
  rejection-text-ip-in-cc-rdns
  rejection-text-ip-in-rdns-keyword-blacklist
  rejection-text-local-recipient
  rejection-text-max-recipients
  rejection-text-missing-sender-mx
  rejection-text-rdns-blacklist
  rejection-text-recipient-blacklist
  rejection-text-reject-all
  rejection-text-relaying-denied
  rejection-text-rhs-blacklist
  rejection-text-sender-blacklist
  rejection-text-smtp-auth-required
  rejection-text-timeout
  rejection-text-unresolvable-rdns
  relay-level
  rhs-blacklist-file
  rhs-whitelist-file
  run-as-user
  sender-blacklist-entry
  sender-whitelist-entry
  smtp-auth-level
  tls-level

* An example spamdyke.conf has been provided.