One of the major reasons we are considering using this system for dealing with general departmental inquiries is so that we could have multiple distributed people working from the same list of tickets at the same time without conflict.  Otherwise, for our purposes, we might as will just have a common gmail account, and have everyone log in at the same time and have at it.  

One major problem with that method is that you don't know if someone else is answering the same email at the same time as you are.  A ticketing system should solve this, by immediately assigning and locking the ticket as soon as any agent STARTS making any changes or adding any comment to a ticket.

It is too late to assign the ticket to the agent after they have already typed in their response and sent it.

...And if I am a second agent looking at / modifying the same ticket, I should be at least WARNED that another agent has modified the ticket before I am able to add/send my response.

Other ticketing systems handle this... it seems like a really essential feature.