You can manually mark tickets as spam by filtering tickets with suspicious content so that such undesired emails don't clutter your helpdesk. Here’s how you can mark an email with a specific subject or description as SPAM through automations.
Navigate to Admin from the menu. Under Workflows, select Automations.
Choose the Tickets tab and under Ticket Creation, click on the New Rule button.
Give your rule a name.
Under the On tickets with these properties: section,
select Match ALL of the below radio button,
In Tickets, select If Subject or Description from the dropdown,
select contains, and then enter the keywords to be detected.
Click on Add new condition option.
In Tickets, select If Requester Email from the dropdown,
select Is, and then provide the email address.
Under the Perform these actions: section, choose Mark as spam.
Click on Preview and Save, and then Save and enable.
You can view these tickets marked as SPAM under the Spam folder on your Tickets View page.