You can turn each of the six alert types on or off for your email. This only changes your own inbox. Each teammate chooses their own.
Click your avatar at the bottom of the left-hand menu to open Account Settings.
Scroll to Email Preferences.
Turn each alert type on or off. Changes save straight away.
You can also click Settings at the top of the Alerts page to change the same settings.
To change which alerts go to Slack, see Send alerts to Slack. To stop alerts for one ad account only, see Mute alerts for an ad account.