If you want to remove any validated e-mail addresses that you have used for your InsaneJournal account (so your password can't be sent to that address), go to [https://www.insanejournal.com/tools/emailmanage.bml] for more information.
Please note that the e-mail address you first used to create your account cannot be deleted. To delete any other e-mail addresses in your history you must be using an e-mail older in your e-mail history than the one you wish to delete.