diff --git a/print_mail/print_mail.inc b/print_mail/print_mail.inc
index f00838f63ffb121eccda2ef4ea0ff44950ca4096..9617f9f3957a7caff3a738e778406521710fc393 100644
--- a/print_mail/print_mail.inc
+++ b/print_mail/print_mail.inc
@@ -179,7 +179,7 @@ function print_mail_form_validate($form, &$form_state) {
   }
 
   // All new-lines are replaced by commas
-  $to_addrs = preg_replace('![\r|\n|,]+!', ',', $form_state['values']['txt_to_addrs']);
+  $to_addrs = preg_replace('![\r|\n|,]+!', ',', trim($form_state['values']['txt_to_addrs']));
   // Create an array from the string
   $to_array = explode(',', $to_addrs);
   // Verify each element of the array