When an action is Dynamically Targeted (By Property or By Group), the client has to download the action and check the Targeting Relevance to determine whether the client is among those targeted. It only has to evaluate the Targeting Relevance at first, which ideally should be less impactful.
On the client you may observe that “Action ####.fxf” is present. If it was issued by a Master Operator, the file will be in the actionsite folder; otherwise it will be in the opsite### folder of the non-mo operator who issued it.
If an action is Statically Targeted, by selecting computers or entering their names, the action will instead be found in the client’s mailboxsite.
If a dynamically-target action is not relevant to the client, the action does not appear in the client log, though a “gather” message for the actionsite, opposite, or mailboxsite may be present.
Edit - I may need to double-check that statically-targeted actions go into the mailboxsite