Unable to send emails

I am unable to send, reply, forward an email from my internet browser on my computer, however the read, delete etc functions still work.  All functions work fine using  the web browser on my blackberry.  On the computer I click on the reply, forward etc, and the white dots slide across the screen like it is processing the request but then never does anything but stay at the message screen. Why does it not work on my web browser on the computer? And how do I fix it?