We've got more in store for this feature set, but we're really excited about this as a start - we use it ourselves at beanstalkapp.com and I know that a number of people HN were using the beta.
I'm happy to answer any questions, or field any ideas you might have.
Hey, finally it launched, will definitely come in handy.
I found a bug in the docs:
On http://developer.postmarkapp.com/developer-inbound-parse.htm...
the link named 'API developer email list' links to 'file://localhost/Users/alexhillman/Sites/wildbit/postmark-design/docs/groups.google.com/group/postmark-api-developers/'
I'm happy to answer any questions, or field any ideas you might have.