CRM 2015, Server Side Sync and Office 365

Hi All,

We are trying to setup an incoming email profile where we can receive emails sent to a specific email address and convert them to a lead. The email address is of Office 365 and CRM 2015 is on premise. So far we have created an email server profile and a mailbox. But we are getting impersonation error. Can someone help me setting up the incoming profile so that we can successfully receive the email in CRM?