■ You can't register email addresses that aren't based on RFC (Request For Comments), because there's a possibility you can't send or receive emails.
■ The examples are as below.
* These email addresses aren't based on RFC.
- "period" and "dot" are placed on address head or end
- "period" and "dot" are continuously used in address
- Unavailable words ,like "slash" , "comma", "dollar", "sharp" are used in address