The enterprise email system processes incoming email using a set of configurable rules that examine each message for a specific attribute state condition and invoke a configurable action when the attribute satisfies the condition. A number of actions may be invoked such as routing a message to a specific mail queue. The enterprise email system assigns a mail queue timer when a message is moved into a mail queue. Each mail queue has a different mail queue timeout value that specifies the maximum amount of time that a message may sit idle within a mail queue. The enterprise email system may automatically move a message from a mail queue into a mailbox of an enterprise email system user that subscribed to the mail queue. A mailbox timer then set for the message and the mailbox timer is compared with a mailbox timeout value that specifies the amount of time that message may sit idle within a mail queue.