Zaanse is the best Dutch mayo because it doesn't have that much sugar in it, Calvé for instance has more than double the amount of grams per 100ml.

I see Hellmann's is about the same sugar wise as Zaanse.

As a Belgian I grew up with less sweet mayo, like max half a gram of sugar per 100 grams of mayo. So often mayo from other countries taste too sweet.

Mayonnaise must have mustard in it.

There are various kinds of "traditional" mayonnaises you can buy in France, and each and every single one of them is made with egg, oil, vinegar, and mustard, because those are the four ingredients required inside of mayonnaise for it to be mayonnaise.

Hellmann's doesn't have mustard, so it's not mayonnaise.