I'm pretty sure that mayo bought from the store is perfectly fine because it contains preservatives and the eggs that are used are first pasteurized.
The most the heating would do to the eggs is denature the proteins, but as with any food it should probably be refrigerated after heating.
If you heat it and eat it you'll be fine.
Just be sure to refrigerate it afterwards.
Mayonnaise is made from raw eggs...when you heat it to a certain degree and let it start to cool, it breeds bacteria that can cause food poisoning.
As long as it was refrigerated beforehand, and you eat it hot, and not let it cool to room temperature, it should be fine.
:/ Can I still eat it? Like re-heating subs/sandwiches with mayonnaise on them, or other foods made with mayonnaise?
uhhh... i eat heated mayonnaise once O.o