Nice feature of CRM 4.0: Users and system administrators alike have never been fond of the tracking token that CRM places in the email subject line in order to track email replies to the correct account or contact in CRM. In CRM 1.2 and 3.0 this token could be turned off completely, but then it was impossible to track replies to CRM emails. With version 4.0, administrators can still use the tracking token for precise tracking, but CRM now offers the ability to turn off the tracking token and still track most messages. CRM 4.0 uses a combination of the email's sender, recipient and subject to figure out which records to relate inbound email to, even without the token! To turn the tracking tokens off in CRM 4.0, go to Settings > Administration > System Settings, and click on the Email tab. See the image below for the checkbox to de-select to disable the tracking token:

Turn-off-Dynamics-CRM-Email-Tracking-Token