I'd like it to be able to perform more checks, and to display its output
in a better format.
Well ... what are the more checks you would like it to do? I am not sure
what all is possible in this day and age.
But, in regards to "better format" ... I was thinking that it could be used
as part of the tooling for encrypting email. Since post does alias
expansion it would make sense that we could use it to get a list of envelope
recipients. You could provide a switch like -format to give it a mh-format
string to be run on every address.