Check out these:

Jam Lady's Original Hot Mango Jam thread

Mango Raspberry Jam thread

There are several other recipes here for it but these are the most popular ones from past discussions.

Dave

I made mango jam recently. I found that when I added a can of crushed pineapple, it helped to tame the sweetness of the mango, yet the pineapple taste wasn't that discernible.

I also made a mango-strawberry, which, imho, is heaven.

If you are adding hot peppers and not adding acid in the form of vinegar or bottled lemon juice it may be unsafe. The peppers are low acid vegetables, not fruit.
You can use Pomonas pectin and use no sugar or whatever you want. It doesn't have to be that sweet with Pomona's.

If you're talking about the hot mango jam recipe it uses 1/4 cup white wine vinegar.

Mango pickles are a staple of Indian cuisine. Try looking up recipes for Mango pickle or Mango relish - pickles tend to be hotter and relishes tend to be more on the sweet side.

I don't know if the original poster added any vinegar or not. That was my concern.