Subscribe2 and PowWeb

I tried using the Email notifications plugin Subscribe2 for my wordpress blog here:
http://infectzia.net/frank/?page_id=270
as you can see if you try to subscribe, you won’t get a confirmation Email. My site hosted at PowWeb. I’ver read here in the forums that the host has to have a “sendmail” option enabled, but I don’t think that’s the problem. I’ve installed another plugin and tried to register (it’s called “mailing list”) abd it worked! But I still want to use Subscribe2 because that other plugin requires fields like “first name” and it’s a drag for the people who just want to get emails. Did anyone have the same problem with PowWeb and solved it somehow?

P.S.
I forgot to mention that my blog is in Hebrew (irrelevant to the problem. only if you visit my page).