diff --git a/modoboa/extensions/webmail/static/webmail/js/webmail.js b/modoboa/extensions/webmail/static/webmail/js/webmail.js
index e43c741e0..3188a4aed 100644
--- a/modoboa/extensions/webmail/static/webmail/js/webmail.js
+++ b/modoboa/extensions/webmail/static/webmail/js/webmail.js
@@ -951,7 +951,7 @@ Webmail.prototype = {
         var top = $mailheader.outerHeight(true);
 
         $("#body_container").css({
-            top: top + "px"
+            height: $(window).height()*0.58 + "px"
         });
     },