From May 2024, emails from INET contain a digital certificate that allows us to recognise that the email is actually from INET and not from an attacker. The certificate also verifies that no changes have been made to the message during the process between sending the email and delivery.
You can tell that an email is signed with a certificate by the seal icon next to the email, which displays information about the sender after being clicked. The name of the sender, which is always INET MU, is also one of the identifiers.