1. These options are only available to organizations using Enhanced Email.

https://www.infallibletechie.com/2018/09/enhanced-email-in-salesforce.html

2. This feature is available in Lightning Experience only.

3. Check if you have Send Email action set up properly in Lightning Experience.

https://help.salesforce.com/articleView?id=email_send_action_which_one.htm&type=5