Two people have told me that they registered but didn't get a confirmation email.
I have looked for their usernames in the administrative panel but I didn't see their username there.

I have no idea if i'm posting this in the right section, But sorry if it's posted in the wrong place.

Please Help.

~IceeRapidash~

Oh and I got one of them to try to register again but it said:

Sorry, this username is already taken.

did they look in their junk folder on their email? it would be there because some email providers think that the email is an add or spam and put it in there.

go in admin pannel>> Users & Groups>> Inactive users, and activate them!