Hi, thanks for the reply!
"You should be able to configure the default email alert settings when you create resource groups."
I can. However, there's no outgoing SMTP server setting in the email notification configuration of a resource group (see attached), so the emails won't get sent. The SMTP server setting is in Settings -> [vCenter] -> Email settings, which is the part I can't configure (per "Problem #1").
"Can you setup the email notifications from the snapcenter server under Settings>Global Settings>Notifications Server Settings"
You mean from the web interface of the "SnapCenter Plug-In for VMware" appliance? I don't see a "Settings" option in that interface. On the left side there's a "Configuration" button and at the upper right there's a settings gear icon, but neither contain any email-related options.