Concerns About Credit Use with Email Triager Template

Good day support, we enabled the email triager template on a mailbox and it consumed 5000 credits in a day. There were two emails which had pretty lengthy email threads and several attachments which consumed almost 3000 credits. Does the email receiver process the email thread in its entirety? Is this normal to have email threads consume this much credit? It's a simple read of the email and apply a label. Thank you, Brian