comments’ approval e-mail doesn’t work

hello,
I have been using wp for a while and it works like a charm. However since I upgraded wp to 1.5 (and moved the server to serverseed.com)
the email notification doesn’t work anymore.
I already did this: this
I don’t know if the problem is on my server side, but to check I’d like to know if the email notification should work on: serverseed.com
thanks