afaik, post reply email notfications are fine.
I with mkroeker, I don't understand what the issue is either.
I people are clever enough to subscribe to a forum, then one would think the are clever enough to unsubscribe.
If some people are considering new post notifications as spam, then surely a reminder about their options should suffice.
I have a spam policy and am pro-active with enforcing my policy, one spammer once told me one man's spam is another man's income. Now with this Shapeways forum situation the opposite is true, lack of notifications means potential lost income.
I know you can't please all of the people all of the time, but I surely do miss just being able to open an email and find out what someone would like modelled.
Paul