Hello Terry,
in case you would like to use Intrusion Event -> Email alerting feature, you don't have to have configured email settings under Alerts tab. You have to choose under Intrusion Event tab IPS rules against which you would like to trigger e-mail notification whenever a new IPS event occurs and is stored under Analysis -> Intrusion events. This requires to have setup e-mail relay settings under System -> Configuration -> Email notification (use test button in order to confirm that e-mail can be send out of FMC appliance at the first place).
Should you have more questions feel free to ask.
Have fun,
Veronika