--- a/dovecot-example.conf	Sat Aug 28 16:25:42 2004 +0300
+++ b/dovecot-example.conf	Sat Aug 28 19:39:53 2004 +0300
@@ -303,6 +303,17 @@
 # lock file after this many seconds.
 #mbox_dotlock_change_timeout = 30
 
+# When mbox changes unexpectedly we have to fully read it to find out what
+# changed. If the mbox is large this can take a long time. Since the change
+# is usually just a newly appended mail, it'd be faster to simply read the
+# new mails. If this setting is enabled, Dovecot does this but still safely
+# fallbacks to re-reading the whole mbox file whenever something in mbox isn't
+# how it's expected to be. The only real downside to this setting is that if
+# some other MUA changes message flags, Dovecot doesn't notice it immediately.
+# Note that a full sync is done for SELECT, EXAMINE, EXPUNGE and CHECK
+# commands.
+#mbox_dirty_syncs = yes
+
 # umask to use for mail files and directories
 #umask = 0077