Generally, you can use the Dynamics App for Outlook to track instantly emails with a user mailbox. However, as you are using shared queue mailboxes to track the emails sync time following the next rule:

Email synchronization occurs every 5 minutes. When a mailbox has many email messages, the interval can be reduced dynamically to 2 minutes. If the mailbox is less active, the interval can be increased up to 12 minutes. Generally speaking, you can assume that a mailbox will be synced at least once every 12 minutes.

Shared queue mailboxes with low volumes time are nearly 10 minutes instead of 2 minutes and we will suggest any way to manage sync to improve the time of sync in these scenarios.