Lexmark MX432
From the control panel, navigate to Settings > E‑mail > E‑mail Setup > Disable “SMTP Server not set up” error > On.
To prevent the error from happening again, do one or more of the following:
Getting an ‘E‑mail Transmission Failure’ or ‘E‑mail Set up Incomplete’ message? Check out the steps below to troubleshoot the issue.
Intermittent 43.40 error message.