Index: openacs-4/packages/acs-subsite/www/register/user-new.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-subsite/www/register/user-new.tcl,v
diff -u -r1.22.12.5 -r1.22.12.6
--- openacs-4/packages/acs-subsite/www/register/user-new.tcl	25 May 2016 13:07:25 -0000	1.22.12.5
+++ openacs-4/packages/acs-subsite/www/register/user-new.tcl	28 May 2016 09:54:42 -0000	1.22.12.6
@@ -18,6 +18,11 @@
             ad_complain "return_url contains invalid character"
         }
     }
+    valid_email -requires email {
+        if {![regexp {^[\w.@+/=$%!*~-]+$} $email]} {
+            ad_complain "invalid email address"
+        }
+    }
 }
 
 set registration_url [parameter::get -parameter RegistrationRedirectUrl]