Switch CI_Email::$validate to On by default

Relevant: #4844

1 files changed, 14 insertions, 0 deletions

diff --git a/user_guide_src/source/installation/upgrade_320.rst b/user_guide_src/source/installation/upgrade_320.rst
index 942a8a3b5..352f85f71 100644
--- a/user_guide_src/source/installation/upgrade_320.rst
+++ b/user_guide_src/source/installation/upgrade_320.rst
@@ -98,6 +98,20 @@ value (previously, it just set the host to the default '127.0.0.1').
 Therefore, if you've added a configuration that only sets e.g. a ``port``,
 you will now have to explicitly set the ``host`` to '127.0.0.1' as well.
 
+Step 6: Check usage of the Email library
+========================================
+
+The :doc:`Email Library <../libraries/email>` will now by default check the
+validity of all e-mail addresses passed to it. This check used to be Off by
+default, and required explicitly setting the **validate** option to ``TRUE``
+in order to enable it.
+
+Naturally, a validity check should not result in any problems, but this is
+technically a backwards-compability break and you should check that
+everything works fine.
+If something indeed goes wrong with that, please report it as a bug to us,
+and you can disable the **validate** option to revert to the old behavior.
+
 Step 5: Check usage of doctype() HTML helper
 ============================================