Request for a new validation code

There seems a problem that the validation emails are sent to the spam box or some users never get the validation email at all. so is it possible that the user can request for a new validation code, or is it possible to give the option that user can register again with the same email address.

In yahoo and hotmail the validation mails are sent to the spam box and they will be automatically deleted after a few days. there is also a delay in getting the message in the spam box of yahoo. so users cant validate their account, and since the email is already in the elgg db, its not possible for them to register oncemore. any idea? Thank you