删除用户名，因为用户名是通过Facebook发送电子邮件的一种方式。

Facebook got rid of the username because the username is one way of sending emails via Facebook.

例如，给定url http：// www。 facebook.com/sebastian.trug

相应的Facebook电子邮件将是 sebastian.trug@facebook.com

the corresponding Facebook email would be sebastian.trug@facebook.com

如果通过电子邮件发送，将直接收到消息（如果消息设置设置为 public ），否则为其他收件箱。

which, if emailed, would be received to messages directly (if the message setting is set to public), otherwise to the other inbox.