As per the documentation:
Single emails sent using the Salesforce application don't count toward this limit. There’s no limit on sending individual emails to contacts, leads, person accounts, and users in your organization directly from account, contact, lead, opportunity, case, campaign, or custom object pages.
Not sure what does this means. Does anybody has any idea about it. Is it reference to workflow created on these objects, but I can see there is workflow limit. If it is not then what exactly salesforce is trying to say here.