Forwarders to Yahoo, AOL, AT&T, Bellsouth, Comcast, Gmail, Hotmail and MSN are deleted every hour..
As these mail providers deal with SPAM in such a way that if an email that was forwarded to your provider account is labeled as SPAM, it follows back to the last address it came from which would be your website IP and marks you as the spammer.
Then pretty soon you can not send or get messages at all as you are on all sorts of spam list or IP Blocking list.
The solution† is to either have that mail provider account go get POP your hosting mail or even better still have a program like outlook , or outlook express, windows mail etc go and get ALL your mail even from the provider and from hosting and now you have it all in one place. That is what we do.. lot simplier that way.