Suppress SPAM comment notification
Ticking this checkbox prevents comments that have been marked as SPAM by another plugin from triggering a ‘New Comment / Awaiting Moderation’ notification. An example of a compatible plugin is Akismet.
Default Email Format
This sets the default format of emails sent out from WordPress to either Plain Text (no formatting) or HTML Formatting. Please note that this applies to all emails sent via WordPress, including those from other plugins.
Allow Usage Tracking?
For more details on this checkbox, please see this document.