Anti spam features, help you filter out suspected spam messages before they reach your team's inboxes.  All incoming emails are processed for Spam based on the IP Address and Domain .You can add an email address or domain to the Allowlist or Blocklist to control who can send you emails.

If you still notice Spam emails in your Inbox, use the mark as spam option to send the mail to the spam folder.
Learn more about anti spam feature in Zoho TeamInbox.