I have restricted "Sending Outgoing Email" but the mail account can still send mail to other mail accounts on same server

In "cPanel > Email Accounts" I have restricted one mail account to send mail out by selecting "Suspend" in "Restrictions > Sending Outgoing Email" I then entered the mail account from cPanel interface ("Check Mail" button), then I tried to send, and it can still send when the recipient is on the same server even if it belongs to another cPanel account/domain. :oops: The restircion works well when the recipient is a mail account on another server (i.e. a Yahoo mail account) Is this normal?