@Override
 public String activateSubscription() {
   try {
     String token = this.getToken();
     INewsletterManager newsletterManager = this.getNewsletterManager();
     String mailAddress = newsletterManager.getAddressFromToken(token);
     if (mailAddress != null && mailAddress.equals(this.getMailAddress())) {
       newsletterManager.activateSubscriber(mailAddress, token);
     } else {
       return INPUT;
     }
   } catch (Throwable t) {
     ApsSystemUtils.logThrowable(
         t, this, "activateSubscription", "Errore durante l'aggiunta di una sottoscrizione");
     return FAILURE;
   }
   return SUCCESS;
 }