Companies often use email accounts to track various customer responses to ads, promotions, web postings, etc. So if your company domain was widgets.com you could use an email addresses like sales@widgets.com, specialoffer@widgets.com, fallsale@widgets.com, springsale@widgets.com, and so on. It's a modern day version of codes people used to add to their physical addresses so they could track where snail mail customer orders came from.
As these change frequently and are updated regularly, it's impractical to set them up individually in an email program as individual accounts. So, when they are set up, they are simply redirected to the accounts of employees designated to handle such email. They can be set up simply as aliases as well, and we use both methods depending on our needs.
At any rate, when the email arrives it's a matter of a few simple rules to sort it to appropriate folders. Yes, I know you 'can' have Mail check them all individually Austin, it's very cumbersome to have to go to each employees email program and set up a new account every time. It's much easier to set up an alias or a redirect from the server. Additionally, we don't want the replies to come from the account it was sent to since a representative will be replying personally.
All of this works splendidly until Mail marks the occasional good message as junk. For the most part it's accurate, but it's less so for the accounts which are new. Given this, it's easier to search the junk mail for good messages if we sort it first by intended recipient. This sort takes seconds using the search bar, but it would be much easier to automate it using a smart mailbox. It's a shame smart mailboxes won't search junk folders.