diff --git a/src/Symfony/Component/Mailer/README.md b/src/Symfony/Component/Mailer/README.md
index 0f70cc30d7..d6fc297909 100644
--- a/src/Symfony/Component/Mailer/README.md
+++ b/src/Symfony/Component/Mailer/README.md
@@ -3,6 +3,11 @@ Mailer Component
 
 The Mailer component helps sending emails.
 
+**This Component is experimental**.
+[Experimental features](https://symfony.com/doc/current/contributing/code/experimental.html)
+are not covered by Symfony's
+[Backward Compatibility Promise](https://symfony.com/doc/current/contributing/code/bc.html).
+
 Resources
 ---------