Email settings
From MoodleDocs
Location: Administration > Server > Email
Allowed and denied email domains
Authentication may be restricted to particular email domains when using Email-based self-registration so that, for example, only students with a university email can login.
Support
Moodle1.9
From Moodle 1.9 onwards, a support name, support email and support page may be set up for users requiring general help.
If set, emails from Moodle regarding password setting/resetting, password change confirmation, password and account confirmation will list the support name, support email and support page at the bottom of the email.