Docebo help says this:

not sure it’s helpful though...Not sure I've ever seen anything come from Docebo to users via this email anyway...it maybe a relic of what used to happen? Maybe support would know better?

Heard back from Docebo rep, alert messages are any action that is “taken on behalf of the system”, background job completed, password reset email, schedule reports, etc. 

Sharing incase someone else is interested. 

@dianex.gomez oh right that’s it! thanks for confirming...forgot all about those notifications...lol