Lexmark XC2335
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:
Does an "SMTP server not set up" error message appear on your printer? Check out the following steps to troubleshoot the problem.
Here are steps on how to set up Gmail SMTP server for Lexmark 2016 up to the latest devices.