Outbound email address not sending

I've configured a custom outbound email address. In the settings, the new email address passes the checks for 'Verified domain', 'SPF record is valid', and 'DKIM record is valid'.

However, when I then do a test email or directly test on our landing page, I don't receive an email. I've checked my spam folder and there's nothing there.

It's not clear to me where the issue is. How should I debug this?