Recommended Scan to Email settings
SMTP Server Name:
Port number for sending/receving E-mail: 25
SMTP - SSL/TLS Communication: Disabled
Maximum Data Size per E-mail: 25MB (current limit in O365)
Always set the machine E-mail Address which can be firstname.lastname@example.org (such as XeroxScanner@ucdenver.edu)
There is no user-authentication or user-logon needed for scanner settings.