Pls move the thread to Products (Move link at the right).
You can't eliminate automated clicks from mail scanners, and at this point there is no way to reliably detect or exclude them. That's the idea, after all: they are meant to be indistinguishable from human clicks in order to detect malicious sites.
It's reported that Marketo is working on functionality that would allow them to heuristically detect + discard mail scanner clicks. Presumably they'll do this by batching hits (as opposed to one-at-a-time, as tracking typically works) and then deciding whether the batch appeared automated.