Intellego magic and magic resistance

Could some kind soul give me a clarification of how Intellgo magic responds to magic resistance?

Under fourth I think the situation was that scrying magic that fetched an image of a target succeeded even where the magic resistance was successful, the target would simply be aware of the scrying. Magic that attempted to discover something about the target (mentem, corpus, vim for instance) failed outright and the target was alerted if the magic resistance was successful.

In this edition, I'm not so sure. Any chance of a guide?

any 5e magic is resisted by the specified Target if it has resistance. The type of spell does not matter - it is the Target doing the resisting.
Examples are

  • an Individual Target (the person or object resists if they have MR)
  • a Group Target (initially you specify one person/thing as the lead member - the one you have range to), and they resist the whole spell
  • the spell targets an Area with MR - eg inside an Aegis spell

if the spell as a whole is resisted, it fizzles completely with no result.
if the spell succeeds, the effect takes place - but may still be resisted.
(any 5e magic is resisted if it tries to affect something)

For example: InIm cast on a grog (no MR) with T: Group, may fail to affect (detect) another in the Group who has MR (and if so, they will know they have successfully resisted some effect).
InIm T:Group cast on one who has MR (eg True Faith) fizzles entirely if that one resists.
InIm cast on a Room is resisted first by the Room (or not, most likely) and then by any contents that the spell effect tries to affect (detect)

It is characteristic of 5e MR that it leaves "blanks" where MR resists the spell. Indeed, True Lineages talks of Quaesitors having special training in perception skillls to look for the tiny anomalies between "nothing there" and "no spell result there".