What happens when an email is forwarded to Mailroom?

When an email comes into the Mailroom, it is scanned along with the mailroom rules configured by you. When the email matches the criteria set up in a mailroom rule, the action in the mailroom rule is executed.

For example, if the Criteria is If Email Recipient contains supportteam@vtgr.com and the Action is Create/Update Cases, then a case record is created for every email that comes into supportteam@vtgr.com.