I wonder if "per unique brand presentation" is the clue to the answer. If so, household is limited to one entry per email per day on a unique brand presentation. If there is more than one unique brand presentation (and they are different) then the only limitations appear to be one per household with one entry per email per day.
Well in reading over this that is clear as mud so let me try again:
First unique brand presentation is limited to one per household per email per day.
Second unique brand presentation (if different from first unique brand presentation) is limited to one per household per email per day.
and so on for each unique brand presentation.
Regardless of entry method: either use email, internet, mail, etc. but not all unless rules specify otherwise.
Each morning when I open my eyes I say to myself: I, not events, have the power to make me happy or unhappy today. I can choose which it shall be. Yesterday is dead, tomorrow hasn't arrived yet. I have just one day, today, and I'm going to be happy in it.
- Groucho Marx