I logged into my Vendio account today to find a message from Vendio alerting sellers that this Monday eBay will be expanding support for Paypal Payment Reviews on eBay transactions. Vendio states that now more eBay payments made through Paypal will be reviewed to determine if they are high risk (Vendio is estimating the total will be well under 10%). If Paypal determines a payment is high risk they will place a hold on the funds and notify the seller not to ship while they review the payment.
Reading the Paypal link containing the information, Paypal states that the seller will be notified “within minutes” of payment via email, as well as flags put in your Account Overview and History Pages. I would recommend not relying on email and check your Paypal account throughout the day for these “flags” or even delaying shipment by a day on high value items.