The configuration that one needs to do:
1. Make sure that Process Using (in system settings email tab) is set to Server Side Sync.
2. An email server profile (ESP) record is created for the target email server. For authentication options, if you ant to use a single credential to access all mailboxes (Exchange impersonation), you can choose the option of profile specified credentials
and supply common credentials in the ESP form. If you want to use separate credentials for every user/queue, then you should choose user/queue provided credentials option in ESP form and individual owners of user/queue should set the username/password in the
mailbox form.
3. Mailboxes of users/queues that need to use SSS have appropriate Synchronization Methods set to SSS and Email Server Profile lookup is pointing to the ESP record created above. This can be done by using bulk edit on mailboxes grid or by first setting the
desired values in default email settings in system settings and then selecting the appropriate mailbox records and clicking Apply Default Email Settings button on the ribbon.
4. Selecting desired mailbox records and clicking on test and enable mailboxes button in the ribbon.
For troubleshooting, you should look for alerts in mailbox records. Sometimes a button on alert called Show Details is available that can give Exchange Error Code. You can also get detailed error information in CRM traces of the async service machine.
HTH
