a1exus on "your host may have disabled the mail() function."

I just created new instance on Amazon AWS EC2 and installed WordPress, yet when I tried to use Lost Password feature, and I received following message on my screen:

The e-mail could not be sent.
Possible reason: your host may have disabled the mail() function.

What do I need to do, for WP to work? I didn't disable mail() function:

[root@ip-10-150-53-42 html]# php -i | grep sendmail_
sendmail_from => no value => no value
sendmail_path => /usr/sbin/sendmail -t -i  => /usr/sbin/sendmail -t -i
[root@ip-10-150-53-42 html]#

I have postfix running and I see other emails are going through without any issues.