Most mayonnaise and aioli recipes call for only egg yolks instead of whole eggs as found here. I prefer to use whole eggs because the whites give you a good moisture buffer (keeping the mayo from thickening too quickly), but egg whites are also highly alkaline, which helps prevent bacterial growth.

If you plan on serving this mayonnaise to people with week immune systems (such as young children or the elderly), I would highly recommend using pasteurized eggs which are available at most super markets.