Change email address that registration emails are sent from

I wish I knew.

Look for wp-includes/pluggable.php

line 354
$from_email = 'wordpress@' . $sitename;

line 976
$wp_email = 'wordpress@' . preg_replace('#^www\.#', '',

change to somethingelse@

Edit: Claytonjames was faster in responding and his plugin solution is better, so you don’t have to change the core file at each update.