Del

FYI many banks have software that lets you know if something was sent with a pixel tracker, and an option to decline sending an open notice and show it as unopened (which I always click). I personally get a lot of open receipt pop-ups from networking emails... don't think people are intentionally sending visible ones, so some of them are definitely getting caught by the software. 

It's also just WAY too early to be sending follow up emails for SA28 when that doesn't kick off for months. What do you expect them to do, hop on another call and say the exact same stuff they said last time, say "thanks bro, that's cool"? 30-50% of the people you are networking with will also be out of IB in a year. Ultimately these people are responding to prospects to be kind and because people helped them, they are not looking to make a new friend with a college freshman who emails them constantly nearly a year before recruiting.

I would wait until you start sophomore year to really network as then they can actually start tracking your resume in the process, add you to the banks' networking trackers etc. I get you are eager and that's great, but right now you are kind of wasting both your and their time when you are so far out from recruiting.