Queue/Comment email addresses


I’m just wondering when the queue email address and comment
address are actually used, from both the web interface and
any emails to the queue via email.

Since RT runs on our mail server, putting in an email address
local to the system obviously won’t generate any external mail.
Some of our customers however make their own aliases pointing
to their queue address, but obviously get replies from the queue
with the queue address, not their alias.

So i’m wondering if I actually put in an external address for the
queue, whether there would be a lot more overhead in delivering
comments/queue related mail back to RT.