[Email Security] Add text add-ons warning (#24037)

* [Email Security] Add text add-ons warning

* Clarification

* Specify body email is going to be reduced

* Update src/content/docs/cloudflare-one/email-security/detection-settings/configure-text-add-ons.mdx

Co-authored-by: Jun Lee <[email protected]>

---------

Co-authored-by: Jun Lee <[email protected]>

Author: 2 people

src/content/docs/cloudflare-one/email-security/detection-settings/configure-text-add-ons.mdx

@@ -7,6 +7,10 @@ sidebar:
 
 You can create custom labels to be used as the subject or body prefix for emails with specific dispositions.
 
+:::caution
+If you currently do not have text add-ons enabled, configuring text add-ons will add a banner to the subject line. As a result, the subject line and the email body will be reduced.
+:::
+
 ## Subject prefix
 
 To configure a subject prefix: