+Version 4.61
+------------
+
+PH/01 There is a new global option called disable_ipv6, which does exactly what
+ its name implies. If set true, even if the Exim binary has IPv6 support,
+ no IPv6 activities take place. AAAA records are never looked up for host
+ names given in manual routing data or elsewhere. AAAA records that are
+ received from the DNS as additional data for MX records are ignored. Any
+ IPv6 addresses that are listed in local_interfaces, manualroute route
+ data, etc. are also ignored. If IP literals are enabled, the ipliteral
+ router declines to handle IPv6 literal addresses.
+
+PH/01 There are now 20 of each type of ACL variable by default (instead of 10).
+ It is also possible to change the numbers by setting ACL_CVARS and/or
+ ACL_MVARS in Local/Makefile. Backward compatibility is maintained if you
+ upgrade to this release with existing messages containing ACL variable
+ settings on the queue. However, going in the other direction
+ (downgrading) will not be compatible; the values of ACL variables will be
+ lost.