Hi WesOdom,
Thank you for reaching Microsoft Community.
May I know which Surface Slim Pen are you using? Is it the 1st version or the Surface Slim Pen 2? See: Identify your Surface Pen and features (microsoft.com)
How about about when you do a tap and hold on the email you want to delete (instead of just hovering the pen) using the pen, does the options for a right-click comes up including the Delete option? Does this work?