I installed bbPress version 0.8.2.1 on Windows XP Pro SP2 with Apache 2.2.4 and PHP 5.2.3. I installed a few plugins, and everything worked fine. However, when I tried to register a new user for testing, I couldn't receive the e-mail with the password.
I checked the error log and found this:
[Sat Aug 18 21:18:09 2007] [error] [client 127.0.0.1] PHP Warning: mail() [<a href='function.mail'>function.mail</a>]: Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set() in D:\\Program Files\\Apache Software Foundation\\Apache2.2\\htdocs\\forums\\bb-includes\\registration-functions.php on line 105, referer: http://127.0.0.1/forums/register.php
Most things on Apache and PHP are set to default, so I'm not sure if I skipped any processes. I've been having trouble with SMTP for a long time now.