lowercase email

In both PunBB 1.2.14 and 1.3 I found such expressions:

    $email = strtolower(trim($_POST['req_email']));

It is incorrect! In general, local part (before "@" symbol) of email address is case-sensitive.
dArt@somesite.com and dart@somesite.com is different, as a rule.
Exception is Postmaster@... only
This drawback can follow errors. For example some user cannot restore they password.

Look at this please: http://en.wikipedia.org/wiki/E-mail_address
"the local-part "MUST BE treated as case sensitive"
"In particular, for some hosts the user "smith" is different from the user "Smith". "