How does the CRM Email router set the RegardingObjectId on incoming emails

We have a system setup where complaints from a website form are emailed to an address and subsequently picked up by the email router and placed in a queue. Users then create a case from these emails (custom code create the case and populates it based on the email content and the queue it arrived into)

Some of the emails are coming in and the regarding object is set to an existing case even though the email and the case are not related. My guess is that this is something to do with the fact that the emails are coming into the queue from t开发者_C百科he same web address (complaints@abc.com)

Can somebody explain to me the criteria the email router uses for setting the regarding object of an incoming email

Thanks, Neil

Looks like you are another "victim" of a feature called Smart Matching. For info on what that is and how to disable it, look here.