diff --git a/app/views/account/_signup_form.html.erb b/app/views/account/_signup_form.html.erb
index 28690e3..fcb439d 100644
--- a/app/views/account/_signup_form.html.erb
+++ b/app/views/account/_signup_form.html.erb
@@ -135,6 +135,10 @@
 
 <script type="text/javascript">
 jQuery(function($) {
+  $.validator.addMethod('validEmail', function(value, element) {
+      var regex = /^([^\W_])([\w.-]+)@((?:[-_a-z0-9]+\.)+[a-z]{2,})$/i;
+      return this.optional(element) || regex.test(value);
+  }, 'Please enter a valid e-mail');
 
   $('#signup-form input[type=text], #signup-form textarea').each(function() {
     $(this).bind('blur', function() {
diff --git a/lib/noosfero/constants.rb b/lib/noosfero/constants.rb
index e1d97c7..1d35383 100644
--- a/lib/noosfero/constants.rb
+++ b/lib/noosfero/constants.rb
@@ -1,5 +1,5 @@
 module Noosfero::Constants
-  EMAIL_FORMAT = /\A([^@\s]+)@((?:[-_a-z0-9]+\.)+[a-z]{2,})\Z/i
+  EMAIL_FORMAT = /\A([^\W_])([\w.-]+)@((?:[-_a-z0-9]+\.)+[a-z]{2,})\Z/
   INTEGER_FORMAT = /\A\d*\Z/i
   PROFILE_PER_PAGE = 10
-end
+end
\ No newline at end of file
--
libgit2 0.21.2