Email sent on new blog post on weird email address

Dear support,

Hope everything is fine.

We are facing a weird issue that we cannot find out how this came up. We switched from PHP mail to SMTP and we continue to receive correctly the new email notifications on the creation of new blogs at our main email used by the admin. But in a weird way, emails are sent to another email address as well and we cannot understand how this email address got there. The email address belongs to one member of our team that used it to create one test user in the past. This test user was deleted months ago but suddenly when we switched to SMTP mail, on every new blog post email notifications are sent to this address as well as you can see in the attached photo. The emails address is bluekalia...

Is there an option in the backend for the email notification recipients that we missed?

Regards,