feat(sa-learn): Added cron script to learn spam/ham

Script checks user inbox and spam to learn what is/isn't spam.

MR !1

include/bin/spam-learn.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+set -e
+
+POSTMASTER="${1}"
+
+# for testing script
+#POSTMASTER=postmaster@example.org
+
+HAM_REPORT=''
+
+SPAM_REPORT=''
+
+for i in /srv/mail/* ; do
+  if [ -d "$i" ]; then
+
+    HAM_REPORT=$(printf "$HAM_REPORT\n\nMailbox: $i\n    $(sa-learn --ham --showdots --no-sync $i/mail/cur)\n")
+
+    SPAM_REPORT=$(printf "$SPAM_REPORT\n\nMailbox: $i\n    $(sa-learn --spam --showdots --no-sync $i/mail/Spam/cur)\n")
+
+  fi
+done
+
+
+if [ "0$POST_MASTER_EMAIL" != "0" ]; then
+
+cat << EOF | /usr/lib/dovecot/dovecot-lda -d "${POST_MASTER_EMAIL}" -o "plugin/quota=maildir:User quota:noenforcing"
+Auto-Submitted: auto-generated
+Date: $(date +'%a, %-d %b %Y %H:%M:%S %z')
+To: ${POST_MASTER_EMAIL}
+From: Mail Server <NO-REPLY@$(hostname -f)>
+Subject: Spam Learning Report $(date +%Y-%m-%d-%H:%M-%Z)
+
+Command: /bin/spam-learn.sh
+
+
+****************** Ham Scan ******************
+$HAM_REPORT
+
+
+
+****************** Spam Scan ******************
+
+$SPAM_REPORT
+
+EOF
+
+fi