We currently have a provider that we use to primarily forward our e-mails to both a hosted Exchange site and to outside e-mail addresses. We have a large # of forwards set-up (maybe 500). They work fine for us but the bandwidth costs are a getting pretty expensive (approx 80GB in email a month) so we're looking for a less expensive alternative (it costs us nearly $150/mo).

I've looked at just hosting this here via a PostFix server and one of the nice front-ends available for it. However, I'm not thrilled with the prospect of being responsible for maintaining yet another server, backups, network connectivity, etc. So I'm leaning towards having this hosted by someone else if possible.

Does anyone have any recommendations for hosting providers? Are there some I should stay away from?