Per GMAIL support site:
Make sure your WHD EMAIL is configured for Secure transport.
Outgoing: "SMTP Server PORT/SSL" SMTP Authentication: SIMPLE selected
Incoming: Account Type "IMAP", INCOMING MAIL SERVER PORT/SSL selected
If you need further assistance, I would recommend contacting SolarWinds and open a Ticket.
Thank you Jimmy, we did configure it that way and continue to see this message daily.