I would prefer this to use a more descriptive name, one that lets devs see what it is about without having to look up and read the RFC. This is a container for valid and invalid email addresses so something like EmailAddresses.

This would also be more appropriate as an enumeration, as shown below:

```
public enum EmailAddress
{
    /*
     * Email addresses consist of a local part, the "@" symbol, and the domain.
     * @see RFC 2822, section 3.4.1
     */
    BASIC_EMAIL("email@example.com"),

    // etc.

    private final String address;

    private EmailAddress(String address)
    {
        this.address = address;
    }

    public String toString()
    {
        return address;
    }
}
```