https://www.phoca.cz/documents/16-joomla ... -in-joomla
If you are not logged in, system doesn't know you and you cannot use email address which is used by some registered user (in case you write your email adress which is registered for you and you are not logged in, system doesn't know you and you cannot use this email address - search this forum, I have explained it here)
- yes, you cannot use email of other person. If you will register into some system, you will not like if somebody other will write messages with your name and with your email address. So the checking the email is necessary. Anonymous users cannot use email adress of some registered user. This is the worst case you can do for your registered usersis it really necessary to check entered email adresses against the user database at all, even when entries are made by guests
