What are the benefits of having two mailboxes as opposed to just one?
Site Configuration - Mailboxes
You might consider having multiple mailboxes configured if your end-users send assistance requests to more than one email address and you want those requests to be routed and handled differently based on the address through which the email is submitted.
With multiple mailboxes, all of the email sent to your mailboxes can be turned into incidents in your Oracle Service Cloud application. However, since those incidents are generated from different mailboxes, you could also create workflow rules to route the incidents from each mailbox to different staff members or staff groups.
If you were to forward all the messages from the various contact email addresses into one mailbox, you would lose the ability to route them to different groups based on their origin. If routing based on origin is not an issue (or any other action that a workflow rule can perform such as appending a standard response) then one email account in Oracle Service Cloud could be used to turn all email messages into incidents.
For incidents created through the Ask a Question page, you can route incidents based on the criteria of your choosing, i.e. based on a specific product, category, custom field value, or the interface name itself. Incidents created from email, however, do not utilize these fields when routing incidents. For email submittals, you may route incidents based on the mailbox through which the incident was submitted.
For additional information, refer to Answer ID 331: Setting up mailboxes in Oracle Service Cloud.