Default sieve port change according to IANA to 4190 as done distribution wide
--- a/config/config_sample.php
+++ b/config/config_sample.php
@@ -50,8 +50,12 @@
 
 /* Port where timsieved listens on the Cyrus IMAP server. Default is 2000. */
 
+/** DEBIAN CHANGE: Depsite upstream's intention Debian changed this default
+ *  distribution wide to 4190 which is thus default here.
+ */
+
 global $sieveport;
-$sieveport = 2000;
+$sieveport = 4190;
 
 /**
  * @var string Space separated list of preferred SASL mechanisms for the
