Contact is receiving email when Opportunity is created

When a new Opportunity record is manually created, the Contact is receiving an email from the on-prem CRM (8.2.1.176). There are no workflows that contain steps that send emails for Opportunities. There are no email templates with this wording under CRM email templates or Click Dimensions email templates. There is nothing under System Jobs. There is nothing under Activities -> All Emails. The previous system admin is no longer at this company.

Any help with tracking down where this email is originating would be appreciated. Thanks.