Is there
any check in mediawiki to determine whether or not the email
address you give it is actually an email address of yours? I think
this is what was meant by "bogus accounts", someone who put
"whatever(a)example.com" or something like that.
If e-mail confirmation is
on, yes: e-mail functions will be disabled until you
go through the confirmation step (it emails you a code, you visit the magic link).
(It's not on on Wikipedia at the moment; we should take care of that sometime.)