...
See the SMS article for details.
Email Task Creation: Email “From” view permissions updated
When a user is creating an email task from the Content Library, in STEP 3 the user can define the From, To, CC, and BCC for the emails. The “From” dropdown will now only show people the user has permission to view. This will mimic the logic in the “Team/Agent” dropdown. Read the Team/Agent Dropdown or Content Library: Emails articles for more detailed information on each feature.
...