Riyas, I'm hoping the following article will help you with the explanation.  Keep in mind that the ECID (experience cloud) is the ID that's must across the various Adobe products (e.g., Analytics, Target, AAM, etc.). https://docs.adobe.com/content/help/en/analytics/components/variables/metrics/metri...

Is there anything in the user agent string to identify these hits?  We capture the user agent string into an evar, and then we can use a segment to filter out any of those hits from reporting and analysis.   Additionally, if everything is related to the one email address (and captured in evar/prop),...

I personally don't like intermixing Tracking Code (aka Campaign variable) with Marketing Channels as it may lead to incorrect insights.  Additionally, both of them have their attribution windows.  If I want to see how the overall Marketing Channel is working, I'll use the Marketing Channels that can...