As the 2020 is FujiXerox, and therefore not available in North America where I, and the forum are located, I can't get you screenshots, but the setting you are looking for is most probably only available in the SMTP server settings, and they are only on CWIS (CentreWare Internet Services) Sorry I can't do more, I can't find a machine with the identical interface to that one that is sold here
So look in CWIS > Properties > Protocol Settings > Email