Are there any email addresses that cannot be used for registration?

In principle, the following email addresses cannot be used as they do not comply with the worldwide Internet communication standard RFC (Request for Comments) .

▼Email address that does not comply with RFC
1. If symbols other than "-", "_", ".", "+", "?", and "/" are included
2. If two or more symbols are used consecutively
3. When symbols are used at the beginning and end (just before @)
Four. If the part before @ is 64 characters or more
Five. If the entire email address is 256 characters or more
If you are using an email address that includes the relevant character string, please register again using a different email address .

*If you use the "SMS/Message app" with your carrier email address, the email may not be displayed correctly.
We recommend registering with a free address such as [] or [].
*If you do not have an email address, please obtain a free email address.