It seems the default tracking pattern is "All emails" when Outlook sync is enabled. We have tried to understand how to set the default tracking pattern to "Only Emails in response to Dynamics 365 email", as this is the most common, or only possible, setting in our company, in regards to GDPR rules. According to the support we have had from Microsoft, this is not possible, due the the fact that some companies want to have "All emails" as default pattern. I believe this cannot be the only wanted default setting, so I hope it will be possible the set any of the sync methods as default for a specific company.