You can set whether to allow sending by users logged in as guests when using a login service, such as SSO-H.
1.
Press 
(Settings/Registration).
(Settings/Registration).2.
Press [Function Settings] → [Send] → [E-Mail/I-Fax Settings].
3.
Press [Allow Unregistered Users to Send E-Mail].
4.
Press [On] → [OK].
If you set [Set Authentication User Dest. to Sender] to 'Off', the address registered in the Device Information settings is displayed at the receiving end. (See "Setting an Authorized User E-Mail Address as the Sender.")
Select [Off] if you do not want to allow sending by users logged in as guests.