We tried to make a change to frenzmail yesterday, and that ended up making it impossible for some people to access their mail. You should not have lost any mail, but the login wasn't working.
Seeing that, we changed back to how settings had been, so if frenzmail isn't working for you now, it should again soon. You can also try this URL:
It goes directly to our account and bypasses www.frenzmail.net. That worked for some people.