In our Service Desk, some of our agents sometimes choose to raise requests via email, rather than within JIRA.
This Service Desk project is configured according to following screenshot to send email notifications when a request is created:
Our agents are not listed in Channels & People => Customers:

To my understanding, this means that they (the agents who raise requests via mail) should not be getting any emails from the "Request Created" notification/event, since (see 1st screenshot above), that notification's "To"-field is configured to send this message to "Customers involved", and none of our agents are, as explained, listed under "Customers".
Yet, when an agent raises a request via mail, that agent does receive said email.
Why? And what can we do to fire off this email only to actual customers (if and when an actual customer raises a request via email)?