Index: openacs-4/packages/acs-subsite/www/shared/send-email.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-subsite/www/shared/send-email.tcl,v
diff -u -r1.10 -r1.10.2.1
--- openacs-4/packages/acs-subsite/www/shared/send-email.tcl	5 Jan 2018 22:40:56 -0000	1.10
+++ openacs-4/packages/acs-subsite/www/shared/send-email.tcl	1 Sep 2021 09:13:20 -0000	1.10.2.1
@@ -3,7 +3,7 @@
     
     @author Miguel Marin (miguelmarin@viaro.net) Viaro Networks (www.viaro.net)
 } {
-    sendto:notnull
+    sendto:naturalnum,notnull
     {return_url:localurl ""}
 } -properties {
     context:onevalue