I'm just curious what some general guidelines are for choosing when to create a shared mailbox or a distribution group for a given purpose. Both are useful for allowing multiple recipients to receive mail through a single external SMTP address. I assume that for high-volume situations, a shared mailbox might be preferable just to reduce database size. It's also easier to "Send as" through a shared mailbox. But other than that, I'm really not sure where one might be favorable to the other.
So if a request comes in to create an external SMTP address to deliver mail to multiple internal users, what kinds of situations would prompt me to choose a DG or a shared mailbox?
I'm working in Exchange 2010, but I think the answers I'm looking for should be relatively independent of the platform.