diff --git a/src/site/xdoc/download.xml b/src/site/xdoc/download.xml
index a9b62025..1cb8346f 100644
--- a/src/site/xdoc/download.xml
+++ b/src/site/xdoc/download.xml
@@ -39,7 +39,9 @@
                         </a>
                         <br/>
                         and follow instructions at
-                        <a href="macosxsetup.html">DavMail Setup on Mac OS X</a>
+                        <a href="macosxsetup.html">DavMail Setup on Mac OS X</a><br/>
+                        Note to OSX Mountain Lion users: you need to disable Gatekeeper (at least temporarily) to avoid
+                        the <code>DavMail is damaged and can’t be opened</code> message.
                     </li>
                     <li>
                         <strong>Debian Linux (Ubuntu):</strong>
diff --git a/src/site/xdoc/macosxsetup.xml b/src/site/xdoc/macosxsetup.xml
index 20c294b0..5678dc1f 100644
--- a/src/site/xdoc/macosxsetup.xml
+++ b/src/site/xdoc/macosxsetup.xml
@@ -11,6 +11,9 @@
     <body>
 
         <section name="DavMail Setup on Mac OS X">
+            <p>Note to OSX Mountain Lion users: you need to disable Gatekeeper (at least temporarily) to avoid the
+                <code>DavMail is damaged and can’t be opened</code> message.
+            </p>
             <p>Older OSX releases include Java 5, this version does not support Tray icon,
                 and DavMail uses a dedicated frame instead. An upgrade to Java 1.6 will enable tray icon.
                 Recent OSX versions either include Java 6 or can install it automatically on first Java application
