[ci skip] Add a changelog entry for #4765
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index a8f9d53..91a59c4 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -36,6 +36,7 @@
 -  Fixed a bug (#4804) - :doc:`Query Builder <database/query_builder>` method ``insert_batch()`` could fail if the input array pointer was modified.
 -  Fixed a bug (#4962) - :doc:`Database Force <database/forge>` method ``alter_table()`` would fail with the 'oci8' driver.
 -  Fixed a bug (#4457) - :doc:`Image Manipulation Library <libraries/image_lib>` method ``get_image_properties()`` didn't detect invalid images.
+-  Fixed a bug (#4765) - :doc:`Email Library <libraries/email>` didn't send the ``User-Agent`` header without a prior call to ``clear()``.
 
 Version 3.1.2
 =============