One real problem that might happen is you'll make OACS dependant on qmail. For some people this might be a
problem. Some people can react rather badly to running qmail (but are happy running buggy and insecure software, go figure).
Now, there is the mess822 package (http://cr.yp.to/mess822.html) which includes "new-inject" which you can run with the -n option to create a correctly formatted message with message id and output it to standard output, which could be use to feed to any sendmail type wrapper.
We could add the full name by formatting the from header
like:
From: OpenACS Q/A Forum <mailto:notification-56476-2960@openacs.org>
Instead of
From: mailto:notification-56476-2960@openacs.org