Something strang happend when I added an e-mail to my Planner card

Copper Contributor

I took an e-mail and added it to my planner card and all of a sudden everyone that was on the e-mail is now in that Planner card. I can't remove them and they keep on getting the updates. Does anyone know what I did wrong and how I can avoid this in the future? Just as an FYI these were external people from my organization. 

1 Reply
Can you add a screenshot of what you did?