newbie question re Super Admin email address

Quick question – when logged in as Super Admin I note that under ‘Users’ the Super Admin email address is my personal email address; whereas in ‘Settings’ the Network Admin Email field shows a different email address (i.e. admin@mainsite.com) for registration and support emails.

Should these two email settings be the same, or is it in fact good for them to differ (in case, for example, server goes down).

Thanks in advance for any help!