add full-text search support

core/dovecot/conf/dovecot.conf

@@ -18,6 +18,20 @@ dict {
   sieve = sqlite:/etc/dovecot/pigeonhole-sieve.dict
 }
 
+###############
+# Full-text search
+###############
+mail_plugins =  $mail_plugins fts fts_lucene
+
+plugin {
+  fts = lucene
+
+  fts_autoindex = yes
+  fts_autoindex_exclude = \Junk
+
+  fts_lucene = whitespace_chars=@.
+}
+
 ###############
 # Mailboxes
 ###############