I will be putting my 2 weeks in for my causal/PRN WFH job this week. I’ve been with this department for 3 years and have only seen my supervisor a few times. I last saw her virtually for 5 minutes for my annual performance review. Would it be considered unprofessional to submit my resignation letter via email? I only care b/c this job is in the largest healthcare company in my state and I may want to return for a different position / in a different department after i finish grad school.