Canon Maxify Printer & Authentication

Your Canon used authenticated SMTP until MFA was introduced, and its SMTP test now fails although the mailbox credentials worked before. An Authenticator approval is an interactive sign-in; most multifunction printers only implement username-and-password SMTP and cannot complete it. First, turn certificate verification back on and confirm the device supports TLS 1.2 or later. For internal status messages, the cleanest replacement is an HVE account: assign its billing policy, use smtp.hve.mx.microsoft on port 587 with TLS, and authenticate with HVE credentials or OAuth if supported. If HVE is unsuitable, direct send can use your tenant MX endpoint on port 25 without authentication for internal recipients, provided your network allows port 25. SMTP relay is another option when you have a static public IP or suitable certificate. Avoid weakening tenant MFA or security defaults for this printer.