TL;DR version: The user cannot save the Email/Appointment if one of the Recipient/Attendee has an invalid email address. SYMPTOM When the user tried to save the Email or Appointment with certain Contact/Account
TL;DR version: The user cannot save the Email/Appointment if one of the Recipient/Attendee has an invalid email address. SYMPTOM When the user tried to save the Email or Appointment with certain Contact/Account