OK. So this is a really ancient command. Back in the days of the AS/400, when the internet was still this new fangled invention and the question “whats you email address” raised an eyebrow of confusion from most people – there was OFFICEVISION: A green screen clunky word processor and very basic email handling system.
This command simply checks if you have any unread emails in the SNA/DS system.
It’s old and legacy. Leave it alone.