Ulta Beauty rep tells TMZ... "Ulta Beauty sent an email with Kate Spade New York perfume featuring an insensitive subject and we sincerely regret this. Mental health is an important and serious issue in this country. We would never take it lightly. We are sorry to the Spade family and our Kate Spade New York partners as well as our guests. We appreciate your understanding and will do our best to make things better.

Ulta is in hot water after she sent out an email promoting a collaboration with Kate Spade... which refers to the tragic death of the fashion designer.

Ulta's mailing lists were shocked to receive a message Sunday saying, "Come hang out with Kate Spade."... Spade committed suicide in 2018.

The Internet is pursuing the beauty companies full bore... many are wondering who the hell QC's stuff that goes.

Customers and ex-employees have called for a boycott, not surprising.

Spade, as we reported, was found dead in her NYC apartment in 2018. Her body was discovered by her housekeeper. Spade left behind a note for her daughter, explaining to her that it wasn't her fault.

We reached out to Ulta, but she has not responded.