Q: Is it possible to add a collaborator when a ticket is created via the web interface (client side)?
A: NO, currently adding a collaborator from the users portal is not possible.
Q: Is it possible to add a collaborator when a ticket is created via an email to the ticket system?
A: YES, adding a collaborator by an emailed ticket is possible. Just add the collaborator(s) to the CC field of the email.
Why, No Possible ?