You can now post new messages to a Basecamp project directly from your email. Users have asked for this for some time, and it will be a most useful feature. Previously, you could respond to a message from email, and now you can initiate a new discussion.

The trick is to find out your unique email address for projects you want to post to and put that in your address book. Here is the explanation from 37Signals:

http://productblog.37signals.com/products/2010/02/new-in-basecamp-post-a...