Notifications all have the same subject ("Subscribed Event Notification") The details (AGS start, Gateway Offline, etc) are buried in the body of the email.

Simply putting a hashtag in the subject would be better for both human eyes glancing at an inbox, and IFTTT integration.
(IFTTT can trigger different actions based on subject line hash-tags)

e.g. Notification Subjects should look like:
"Subscribed Event Notification #GatewayOffline"
or
"Subscribed Event Notification #BatterySOCLow #AGSStarted"