In case you missed it, you can read every single inbound email that arrives to your Volo server. It’s on the admin interface, the System > Inbox page. Neat for reading whitelisting confirmation emails, and clicking those links.
You can test how it works – pick one of your active domains, then send a blank email to abuse@<that_domain>
Said email will be waiting for you in the FBL section as soon as you refresh the Inbox.