Hi Jorge. A System Administrator can enable this for all users by following these steps.
- Go to Settings >> Defaults >> User Defaults. Select the Compose tab and enable "Warn about common email mistakes prior to sending". Click Save.
- Now go to settings >> Defaults >> User Propagation. Select the Compose tab, put a checkmark next to "Warn common email mistakes before sending" and then click the Propagate Now button.
That will propagate this setting to all users, and they will be prompted if they attempt to send an email that does not contain a subject.
Technical Support Specialist