Why are emails that I've sent or received not in the List View of Activities?
Pipedrive considers emails to be separate from 'email type' activities. While 'Email' is a default activity type, emails that are sent (or received) through the Email Sync or Smart Email BCC features will not be counted as an 'email type' activity.
Scheduled 'email' activities are used to manage future email tasks appropriately, so you do not forget about your correspondence with a customer. If you want your 'email type' activity count to reflect your email count, we recommend creating an email type activity for each email received or sent.