If you kindly bother to read the other threads and replies, you'd know that Yahoo mail service is flaky and some people aren't getting their emails.
Some people are getting their emails, some people are not. There is no fix, unless there is a better email service that is free and allows for hundreds of emails to be sent per day this is what happens, the amount of emails are simply too much for yahoo to handle.
All unactivated accounts are now deleted within 24~48hrs.
Again, you do not need an account to lurk Kureha One, and inactive accounts get purged monthly anyways.