we should add noreply@domain.com address when email is sent from graaasp.
three possible scenarios
1) noreply + "Reply" button in email that opens item 4a
2) Create "email" address for a space, when replay it will add comment for this space (what to do with assets, then?)
noreply howto:
http://webpatrika.blogspot.com/2007/04/creating-no-replydomaincom-account-in.html