Can't send an email

[techdude]

When I compose, reply or forward an email the little popup at the top comes down and says Sending Message and Safari's loading spinner starts to spin, but the loading bar freezes at about 20% and just sits there.  Any idea why it won't let me send an email, but it will let me do everything else?

This is a fresh install, I haven't done anything except that I just installed it.  I am running it on a Linux Server on a Shared Host and yes, my username and password are correct.

Oh...and Roundcube 1.0 works fine by the way...when I downloaded the newest RC today, it didn't work.

[bluezone]

I'm having the exact same problem, but I'm using IIS 7.  PHP works, because the Horde site I'm trying to transition from is working.  Doesn't anyone have any ideas?