diff --git a/single-sign-on/index.md b/single-sign-on/index.md
index 05b19c4059..b03ca418db 100644
--- a/single-sign-on/index.md
+++ b/single-sign-on/index.md
@@ -109,7 +109,7 @@ The following video walks you through the process of configuring SSO.
 
 ### Domain control
 
-Click **Add Domain** and specify the corporate domain you’d like to manage with SSO. Domains should be formatted without protocol or www information, for example, yourcompany.com. Docker currently supports multiple domains that are part of your IdP.
+Click **Add Domain** and specify the corporate domain you’d like to manage with SSO. Domains should be formatted without protocol or www information, for example, yourcompany.com. Docker currently supports multiple domains that are part of your IdP. Make sure that your domain is reachable through email.
 
 > **Note**
 >