Lập email facebook log

Here is the format for a Facebook login email:

username@facebook.com

Where username is the unique identifier chosen by the user when they created their Facebook account.

For example:

Note that Facebook usernames can be any combination of letters, numbers, and underscores, and must be at least 5 characters long. They are case-sensitive, meaning that JohnSmith and johnsmith are considered two different usernames.

Also, Facebook usernames are unique to each account, so if someone tries to use a username that is already taken, they will be prompted to choose a different one.