This is really wierd.
I was about to move the thread to identified issues, but before that:
I just reviewed the code for this and did some tests, and the lost password email is sent with the same functions and from/reply-to addresses as the registration emails sent to the new user.
Could you all in here please try following:
- register a user with an email
- check that this email gets the registration email(s)
- use lost login form to have the username sent
- check that this email is really not received (including in spambox) ?
Thanks