There are 21 preferences, not 17
diff --git a/user_guide_src/source/libraries/email.rst b/user_guide_src/source/libraries/email.rst
index a55f189..39629ec 100644
--- a/user_guide_src/source/libraries/email.rst
+++ b/user_guide_src/source/libraries/email.rst
@@ -43,7 +43,7 @@
Setting Email Preferences
=========================
-There are 17 different preferences available to tailor how your email
+There are 21 different preferences available to tailor how your email
messages are sent. You can either set them manually as described here,
or automatically via preferences stored in your config file, described
below: