Check that the emails don’t end up in your spam filter. Add eveonline@service.ccpgames.com to your contacts, possibly whitelist the address with your mail provider, to avoid the spam filter.
If you still don’t get any codes by email then create a support ticket or send a message to support@eveonline.com, tell them your problem and tell that what you did so far, and ask them to check if your email address has somehow been flagged as inactive or otherwise been disabled.
Good luck!