If you're developing under Windows and would like to see the emails PHP attempts to send out, the following program catches the emails and displays them without actually sending them out. It's not a SMTP server, it's more a SMTP email catcher.
The following settings need to be set in your php.ini:
SMTP = localhost
smtp_port = 25
(the smtp_port needs to be the same port defined in Papercut)
and in your OSCOM Administration:
Admin -> Configuration -> E-Mail Options -> E-Mail Transport Method: smtp
Admin -> Configuration -> E-Mail Options -> Send E-mails: true
You then get notified each time an email is caught and can view the actual email.